Computer Knowledge: Types of Internet Connections in Communication for IBPS and SBI Exams

Types of Internet Connections

1) Dial-Up Connection:
A Dial-up is a method of connecting to the Internet using an existing telephone. Dial-up connection uses the telephone lines to connect to the Internet. The modem connects the computer through the standard phone lines, which serve as the data transfer medium. A modem changes the digital data from your computer into analog data, a format that can be carried by telephone lines. Modem stands for Modulator and Demodulator. ISP refers to the company that provides internet connections to the users. Some popular ISP's, are Airtel, MTNL etc. When a user initiates a dial-up connection, the modem dials a phone number of an Internet Service Provider (ISP) that is designated to receive dial-up calls. The ISP then establishes the connection, which usually takes about ten seconds and is accompanied by several beeping and buzzing sounds.

2) Broadband Connection:
The term broadband commonly refers to high speed Internet access that is always on and faster than the traditional dial-up access. It uses a telephone line to connect to the Internet. Broadband access allows users to connect to the Internet at greater speed than a standard 256 KB  modem or dial-up access. Digital Subscriber Line (DSL): Digital Subscriber Line (DSL) is a popular broadband connection. It provides Internet access by transmitting digital data over the wires of a local telephone network. DSL is the most common type of broadband service. DSL uses the existing copper telephone lines. A special modem is necessary in order to be able to use a DSL service over a standard telephone line.

3) Wireless Connection:
Wireless broadband can be mobile or fixed. Unlike DSL and cable, wireless broadband requires neither a modem nor cable and as a result it can be easily established in areas, where it is not feasible to deploy DSL or Cable. It is a universal wireless networking technology that utilises radio frequencies to transfer data.Wireless broadband connects a two or more devices likes home's or business to the Internet using a radio link between the customer's location and the service provider's facility. Wi-Fi allows high speed Internet connections without the use of cables or wires. Wi-Fi networks can be designed for private access within a home or business or be used for public Internet access at "hot spot" such as restaurants, coffee shops, hotels, airports, convention centres and city parks.

4) Integrated Services Digital Network (ISDN):
It is a digital telephone service that can transmit voice, data and control information over an existing single telephone line. It was the first high speed alternative to regular analysis phone modems. It is widely used for business purpose.

Computer Knowledge: Importance of Internet and Its Services for IBPS, SBI and Other Competitive Exams

Importance of Internet and Its Services

The Internet has gained popularity and emerged as an important and efficient means of communication. The idea of introducing the internet was to allow millions of people to share information and ideas, sound, video clips using their computers across the world. The internet is a world wide network of networked computers those are able to exchange information with each other. It consists of thousands of separately administered network of various sizes and type.

Internet:
Internet stands for International Network, which began in 1950's by Vinit Curf known as the Father of the Internet. The term Internet is derived from two words-Interconnection and networks, also referred to as "Net". Internet is a "network of networks" that consists millions of private and public network of local to global scope. Basically, network is a group of two or more computer systems linked together.

Uses and Working of Internet:
Internet has been the most useful  technology of the modern time which helps us not only in our daily lives but also our personal and professional lives developments. Internet helps us in communication, information, business, social networking, shopping, entertainment, job searching and E-commerce.

The computers on the Internet are connected to each other through the small networks.These networks connected through the gateways to the Internet backbone. The data move around the Internet is controlled by protocols. Under TCP/IP protocol (Transmission Control Protocol / Internet Protocol), a file is broken into smaller parts by the file server called packets. All computers on the Internet, communicate with one another using TCP/IP, which is a basic protocol of the Internet.

History of Internet:
In 1969, the university of California at Los Angels. the University of Utah were connected as the beginning of the ARPANET (Advanced Research Projects Agency Network) using 50 kbits circuits. It was the world's first operational packet switching network. The goal of this project was to connect computers at different universities and U.S defence.

In mid 80's another federal agency, the National Science Foundation, created a new high capacity network called NSF net, which was more capable than ARPNET. The only drawback of NSF net was that it allowed only academic research on its network and not any kind of private business on it. So, private organisations and people started working to build their own networks, which were later interconnected with ARPNET and NSF net to form the Internet.

Computer Knowledge: About Network Topology's in Computers for Competitive Exams

Network Topology's ( Mesh, Star and Tree Topology's)

Mesh Topology: 
It is also known as completely interconnected topology. In mesh topology, every node has a dedicated point to point link to every other node. It provides a bi-directional link between each possible node. This type of network topology contains at least two nodes with two or more paths between them. Mesh topology is robust because the failure of any one computer does not bring down the entire network.

Advantages of Mesh Topology are:

• Excellent for long distance networking.
• Communication possible through the alternate route, if one path is busy.

Disadvantage of Mesh Topology are:

• Long wire or cable length, hence increase in the cost of installation and maintenance.

Star Topology:
In this network topology, the peripheral nodes are connected to a central node, which rebroadcasts all transmissions received from any peripheral node to all peripheral nodes across the network, including the originating node.If the central hub fails, then whole network fails. The protocols used in star topology are Ethernet, Token Ring and Local Talk. A star network can be expanded by placing another star hub.

Advantages of Star Topology are:

• Installation of star topology is very easy as all the nodes are directly connected to the central node or server.
• Easy to detect faults and remove it.
• Failure of single system will not bring down the entire network.
• Allows several types of cables in same network.

Disadvantages of Star Topology are:

• Requires more cable length than bus topology.
• If hub or server fails, the entire network will be disabled.
• Difficult to expand, as the new node has to connect all the way to central node.

Tree Topology: 
This is a network topology in which nodes are arranged as a tree. The function of the central node in this topology may be distributed. A tree topology is an extension and variation of star topology. Its basic structure is like an inverted tree, where the root acts as a server. It allows more devices to be attached to a single hub.

Advantages of Tree Topology are:

• The tree topology simulates hierarchical flow of data. So, it is suitable for applications where hierarchical flow of data and control is required.
• We can easily extend the network.

Disadvantages of Tree Topology are:

• Long cable are required.
• There are dependencies on the root node.
• If the central hub fails, the entire system breaks down.

Computer Knowledge: Network Topology's for Competitive Exams

Network Topology's ( Bus - Ring)

Network Topology: The term "Topology" refers to the way a network is laid out, either physically or logically. Topology can be referred as the geometric arrangement of a computer system. Each computer system in a topology is known as node. Network topology is determined only by the configuration of connections between nodes. In a fully connected network with n nodes, there are n(n-1)/2 direct links.

Bus Topology:

A bus topology is such that there is a single line to which all nodes connected. It is usually used when a network installation is small, simple or temporary. In bus topology, all the network components are connected with a same (single) line. Ethernet is commonly well protocol in networks connected by bus topology.

Advantages of Bus topology are:

• All the nodes are connected directly, so very short cable length is required.
• The architecture is very simple and linear.
• Bus topology can be extended easily on either sides.
• The cabling cost of bus topology is less and requires the least amount of cable to connect computers.

Disadvantages of Bus topology are:

• Diagnosis of fault is difficult. It is difficult to find the problem, if any of the node is facing problem in data communication.
• In case of any fault in data transmission, fault isolation is very difficult. We have check the entire network to find the fault.
• Becomes slow which increase in number of nodes.
• The entire network shuts down if there is an error occurs in the main cable.

Ring or Circular Topology

Ring topology is used in high-performance network where large band with is necessary. The protocols used to implement ring topology are Token Ring and Fibre Distributed Data Interface (FDDI). In ring topology, data is transmitted in form of Token over a network. After passing through each node, the data returns to the sending node.

Advantages of ring or circular topology are:

• Short cable length is required.
• Suitable for optical fibre as the data flow in one direction.

Disadvantages of ring or circular topology are;

• In ring topology, each node is connected in a circular way, with its two neighbouring nodes, so when there is transmission problem anywhere in the network, entire network stops functioning.
• Fault diagnosis is very difficult in a network formed using ring topology.
• In ring topology, every node has exactly two branches connected to it, the ring is broken and cannot work if one of the nodes on the ring fails.
• Failure of single computer affects the whole network.
• Adding or removing the computer disturbs whole network activity.

Note:- We will discuss remaining Three Topology's in coming posts. Happy Reading.....

Computer Knowledge: All about Network Devices for Competitive Exams

Comnputer Knowledge: Network Devices

Network devices are required to amplify the signal to restore the original strength of signal and to provide an interface to connect multiple computers in a network. There are many types of network devices used in networking. Some of them are described below.

1) Repeater: A repeater is a device that operates only on the physical layer of OSI model. Repeaters have two ports and can connect two segments of a LAN. It amplifies the fable signals when they are transported over a long distance so that the signal can be as strong as the original signal. A repeater boosts the signal back to its correct level.

2) Gateway: A gateway is an interconnecting device, which joins two different network protocols together. It holds the information from a website temporarily, so that the repeated access to same website or web page could be directed to the proxy server instead of actual web server. Thus helps in reducing the traffic load.The gateway is a node in a network which serves as a proxy server and a firewall system and prevents the unauthorised access. They are also known as protocol converters. It accepts packet formatted for one protocol and converts the formatted packet into another protocol.


3) Hub: Hub is like a repeater with multiple ports used to connect the network channels. It acts as a centralised connection to several computers with the central node or sever. When a hub receives a packet of data at one of its ports from a network channel, it transmits the packet to all of its ports to all other network channel.


4) Switch: Switch forwards a data packet to a specific route by establishing a temporary connection between the source and the destination. It is a small hardware device that joins multiple computer together within one LAN. Switches work on the data link layer of the OSI model. It helps to reduce overall network traffic. There is a vast difference between switch and a hub. A hub forwards each information packet (data) to all the hub ports, while a switch forwards each incoming packet to the specified recipient.

5) Router: Router is a hardware device which is designed to take incoming packets, analyse the packets, moving the packets to another network, converting the packets to another network interface, dropping the packets, directing packets to the appropriate locations etc.

6) Modem: Modem is a device that converts digital signal to analog signal (modulator) at the sender's site and converts back analog signal to digital signal (demoulator) at the receiver's end, in order to make communication possible via telephone lines. A MODEM is always placed between a telephone line and a computer.

7) RJ11 Connector: RJ11 connector is the typical connector used on two pair, four wire handset wiring. RJ means "Registered Jack", the physical connector interface that is most often utilised for handset wire terminals. RJ11 connector wiring comes in two standard assortments -UTP or Unshielded Twisted Pair and flat-satin cable or the untwisted. RJ11 connectors are used to terminate phone lines, and are typically deployed with single line POTS (Plain Old Telephone Services) telephone jacks.

Computer Knowledge: About Wireless Technology in Data Communication for IBPS, SBI and Other Competitive Exams

Unguided Media ( Wireless Technology)

It is the transfer of information over a distance without the use of enhanced electrical conductors or wires. When the computers in a network are interconnected and data is transmitted through waves, then they are said to be connected through unguided media. Some commonly used unguided media of transmission are;

1) Radiowave Transmission:
When two terminals communicate by using radio frequencies then such type of communication is known as radio-wave transmission. This transmission is also known as Radio Frequency (RF) transmission. These are omnidirectional. Radiowaves are propagate in the sky mode, can travel long distances. Each computer attaches to an antenna that can both send and receive radio transmission.

Radiowave transmission setup has two parts:

• Transmitter: The devices which transmit signals, are termed as transmitter.
• Receiver: The devices which received signals, are termed as receiver.

Advantages and Disadvantages of Radiowaves
Advantages		Disadvantages
1	Cheaper than wired network	Insecure communication can be easily taped.
2	Provides Mobility	It is affected by the weather conditions such as rain, storms, thunder, etc.
3	Easy to use over difficult terrain.

2) Microwave Transmission:

Microwaves are electromagnetic waves having frequencies range from 0.3 to 300 GHz. Microwaves are unidirectional. Microwaves have a higher frequency than that of radiowaves. Microwaves is one of the fastest media for data transmission over communication channel. They can be aimed at a single direction instead of broadcasting in all direction. Microwaves antenna placed on the top of buildings. It consists series of stations approx 30 miles apart. It is used in cellular network and television broadcasting.

Advantages and Disadvantages of Microwaves
Advantages		Disadvantages
1	Cheaper than digging trenches for laying cables and using repeaters.	Insecure communication, as the taping of microwaves is easy.
2	Using microwaves, communication is possible even in difficult terrains.	It is affected by the weather conditions such as rain, thunder, storm etc.,
3		Cost of maintenance, implementation and design is high.

3) Satellite Communication:

The communication across longer distances can be provided by combining radio frequency transmission with satellites. It works over a long distance and fast communication. Satellite communication amplifies signal received from one Earth station, which can be located many thousand of miles away. It is used for communications to ships, vehicles, planes and handheld terminals.

Advantages and Disadvantages of Satellite   Communication
Advantages		Disadvantages
1	It covers a vast range of area.	It is very costly. So, it is preferred to use personal or low budget communication.
2	The wired communication is almost impossible and too costly to use across the continents where the satellite communication proves to be the best alternative.	There is atmospheric loss of transmitted signals.
3	It is very useful in television transmission.

4) Infrared Wave Transmission:

Infra red waves are the high frequency waves used for short-range communication. These waves do not pass through the solid-objects. They are mainly used in TV remote, wireless speakers.

5) Bluetooth

It is a wireless technology used for exchanging data over short distance to create a Personal Area Network (PAN) or piconet invented by Erreiscon in 1994.

Computer Knowledge: Data Communication in Networks for IBPS, SBI and Other Competitive Exams

Data Communication in Networks

Communication:

The term communication means sending or receiving information. When we communicate, we share information or data. This sharing can be local or remote access. A communication system can be defined as the collection of hardware and software that facilitates inter system exchange information between different devices.

Data Communication

Data communication is the exchange of data between two devices using some form of transmission media. It includes the transfer of data or information and the method of preservation of data during the transfer process. This data transfer(communication) is done between a centralised computer and remote terminals or between two or more computer centres over established communication links. Data is transferred from one place to another in the form of signals.

There are three type of signals:

1) Digital Signal: In digital signal, data is transmitted in the electronic form of data. i.e., Binary digits ( 0 or 1).

2) Analog Signal: In analog signal, data is transmitted in the form of radio waves like in telephone line.

3) Hybrid Signal: Hybrid signals have properties of both analog signal and digital signal.

Types of Communication Channels:

The communication channel refers to the direction of signal flow between two linked devices.

1) Simplex Channel: In this channel, the flow of data is always in one direction, with no capability to support response in other direction. This communication is unidirectional. Only one of the communicating devices transmits information and the other can only receive it i.e., Radio, Television, Keyboard, etc.,

2) Half Duplex Channel: In this channel, the data can flow in both directions, but not at a same time. When one device transmits information, then other can only receive at that point of time. Ex:- Walkie-Talkies.

3) Full Duplex Channel: In this channel, the flow of data is in both directions at a time i.e., both stations can transmit and receive information simultaneously. Ex:- Wireless handset (mobile phones)

Communication Media:

Communication media of a network refer to the transmission media or the connecting media used in the network. It can be broadly defined as anything that can carry information from a source to destination. It refers to the physical media through which communication signals can be transmitted from one point to another.

Computer Knowledge: Architecture of DBMS, Advantages and Disadvantages of DBMS for Competitive Exams

Architecture of DBMS 

The architecture of a database system provides a general framework for database system. This means that the system does not provide all the details of the data, rather it hides the details of how the data are stored and maintained.

The Architecture is divided into three levels;

1) Physical Level: It is the lowest level of data abstraction that deals with the physical representation of the database on the computer. It is also known as internal level. It defines how the data are actually stored and organised on the storage medium.

2) Logical Level: It is the overall view of the database and includes all the information that is going to be represented in the database. It describes what type of data is stored in the database, the relationship among the data without effecting to the physical level. It is also known as conceptual level.

3) View Level: This is the highest level of data abstraction which describes the interaction between the user and the system. It permits the users to access data in a way that is customised according to their needs, so that the same data cab be seen by different users in different ways, at the same time.

Advantages of DBMS 

1) Reduction in Data Redundancy: The duplication of data refers to data redundancy. DBMS cannot make separate copies of the same data. All the data is kept at a place and different applications refers to data from centrally controlled system.

2) Better Interaction with Users: In DBMS, the availability of up-to-data information improves the data to be access or respond as per user requests.

3) Improvement in Data Security: DBMS can allow the means of access to the database through the authorised channels. To ensure security, DBMS provides security tools i.e., username and password.

4) Maintenance of Data Integrity: Data integrity ensures that the data of database is accurate. In DBMS, data is centralised and used by many users at a time, it is essential to enforce integrity controls.

5) Backup and Recovery: The DBMS supports backup and recovery subsystem that is responsible to recovery data from hardware, software, virus attack and other failures.


Disadvantages of DBMS 

1) Complexity: The provision of the functionality that is expected from a good DBMS makes the DBMS an extremely complex piece of software. Failure to understand the system can lead to bad design decision, which can have serious consequences for an organisation.

2) Cost of Staff Training: Mostly DBMS are often complex systems so the training for user to use the database is required. The organisation has to pay a lot of amount for the training of staff to run the DBMS.

3) Database Failures: In most of the organisations, all data is integrated into a single database. If database is corrupted due to power failure or it is corrupted on the storage media, then our valuable data may be lost or whole system stops.

4) Cost of Maintenance: We need a high speed processor for processing large size of DBMS software. Similarly database software is also very costly. It means we must upgrade the hardware used for database management.

Computer Knowledge: Database Concepts and Its Components for Competitive Exams

Database Concepts

A database is a collection of logically related information n an organised way so that it can be easily accessed, Managed and updated. Some other operations can also be performed on database such as adding, updating and deleting data. A database could be simple as a single text file with a list of names or it could be complex as a large bunch of text files including some data.

In database, data can be entered through input devices such as keyboard, mouse, touch-screen, etc. Some examples of database are telephone directory, railway timetable, books catalogue, equipment inventory, etc,.

Fundamentals of Database:

For defining database, two terms, which are used frequently with database, should be known.

Data: These are raw and unorganised facts that need to processed such as digital representation of text, numbers, graphical images or sound. Data refer to the values physically recorded in the database e.g., a student's text score is one piece of data.

Information: When data is organised, processed, presented or structured in given context to make it useful or meaningful, it is called information. Information refers to the conclusion or meaning drawn out of it. e.g., the class's average score is the information that can be concluded from the given data.



Types of Database

Database are of three types, namely

1) Network Database: In this type of database, data is represented as collection of records and relationships among data are represented as links.

2) Hierarchical Database: In this type of database, data is organised in the form of trees with nodes. Nodes are connected via links.

3) Relational Database: Relational database is also known as structured database in which data is stored in the form of tables. Where, columns defines the type of data stored in the table and rows defines the information about the data.

Components of a Database:

A database consists of several different components. Each component listed, these are  called an object. In one single file, you can divide your data into separate storage parts (Containers) called tables. View, add and update table data by using query's or on-line command forms. find and retrieve the data you want by using queries and analyse or print data in a specific layout by using reports.

Database components are described below;

Tables: Tables are the building blocks or relation of any relational database model where all the actual data is defined and entered. Tables consists of cells at the intersection of records (rows) and fields (columns). Different type of operations are done on the tables such as storing, filtering, retrieving and editing of data.

Field: A field is an area (within the record) reserved for a specific piece of data. e.g., student number, student name, address, city, state, phone number, current address etc., Field of a table is also known as column.

Record: A record is the collection of data items of all the fields pertaining to on entity i.e., a person. company, transition etc. Record of a table is also known as row or a tuple and the number of records in a relation is called the cardinality of that relation.

Queries: Queries are basically questions based on the data available in a database. A query consists of specifications indicating which fields, records and summaries a user want to fetch from a database. Queries allow you to extract data based on the criteria you define.

Forms: Although you can enter and modify data in datasheet view of tables but you neither control the user's action very well nor you can do much to facilitate the data-entry process. To overcome this problem, forms are introduced.

Reports: When you want to print those records which are fetched from your database, design a report. Access even has a wizard to help produce mailing labels.

Computer Knowledge: Microsoft Access and Its Components for IBPS, SBI and Other Competitive Exams

Microsoft Access

A database is a collection of logically related and similar data. Database stores similar kind of data for a specific purpose that is organised in such a manner that may information can be derived from it, when needed. Microsoft access is an application which allows the creating of databases. Microsoft access is a Relational Database Management System (RDBMS). Access is a tool for managing the database. It allows you to design and create complete databases with quick and easy data entry, maintain them and search for information.

Start MS-Access:

To start the MS-Access software, we need to

Click Start → All Programs → Microsoft Office → Microsoft Office Access 

Components of MS-Access:

MS-Access stores data in its own format based on the Access Jet Database Engine. Access supports some object-Oriented techniques.

Templates: It is a complete tracking application with predefined tables, forms, reports, queries, macros and relationships.

MS-Access includes a collection of database templates, which are described as

• Assets: It is used to create an assets database to keep track of assets, including assets details and owners.

• Contact: It is used to create a contact database to manage information about people.

• Events: It is used to create an events database for tracking upcoming meeting, dealing etc.,

• Faculty: It is used to create a faculty database to keep track of information  about contacts and education history.

• Marketing Projects: It is used to create a marketing projects database to track time-sensitive deliverable and vemlor status for project.

• Students: It is used to create students database to keep information about your students including contacts, about their guardians.

Queries in MS-Access:

Query Type	Description
Select Query	Retrieves data from one or more tables and displays the record set in a datasheet. This is the most common type of query.
Parameter	Prompts the user to enter values that define the query, such as a specified region for sales results or a specified price range for houses.
Cross-tab Query	Arranges a record set to make it more easily visible, using both row headings and column headings.
Action Query	Creates a new table or changes an existing table.
SQL Query	An advanced query that is created by using an SQL statement.

Elements of MS-Access:

In MS-Access, database holds five major elements for every database operation.

( i ) Field Name: It is a label provided for a field that specifies the type of information contained in particular field.

( ii ) Field Type/ Data Type: It specifies the type of data stored in the field such as textual data and numerical data or combination of both. The default size of data type is 50 in MS-Access.

( iii ) Field Length: Field refers length or width to the maximum number of characters that a field can contain.

( iv ) Primary Key: A filed which is used to uniquely identify the records in a table. The primary key cannot contain null value.

( v ) Validation Rule: It is a condition that must be met before the data is accepted into the database.

MS-Access View:

You can create a table by two most popular ways

Database View: It shows the data in the database and also allows you to enter and edit the data but not allow to change the database.

Design View: It allows you to create or change the table and also set the keys.

Filtering Data: It enable to display only those records in a table that meet a specified filter criterion.

Relation Ship: It is a n association between access tables or quarries that use related fields. It is a link between tables and enables us to accessed data from both tables simultaneously. 

Relationship can be divided in three categories;

• One-to-One
• One-two-Many
• Many-to-Many

Attributes: Attributes can be defined as the characteristics of an entity to identify it uniquely. Such as student's attributes are his Roll-No, Section, Name etc.,

Computer Knowledge: System Management Program and Its Utilities for IBPS, SBI and Other Competitive Exams

System Management Program and Its Utilities

System Management Program

It includes an integrated system of programs, which manges the operations of the processor, controls input/output, manages storage resources and provides various support services. Some common examples of system management programs are operating system, device driver and system utilities.

Operating System

It contains of programs, which controls, coordinates and supervises the activities of the various components of a computer system. Its function is to provide link between the computer hardware and the user. It performs all internal management functions (disk access, memory management, task scheduling and user interfacing) and ensures systematic functioning of computer system. It provides an environment to run the programs.

Ex:- MS-DOS, Windows XP/7/8/2000/98

The operating system performs the following functions:

• It recognises input from keyboard, sends output to the display screen.
• It makes sure that programs running at the same time do not interface with each other.
• It is also responsible for security, ensuring that unauthorized users do not access the system.

Device Drivers

A software, which is written with the objective of making a device functional when it is connected to the computer is called device driver. It is a system software that acts like an interface between the device and the user. Every device, whether it is a printer, monitor, mouse or keyboard has driver program associated with it for its proper functioning.

• Device drivers are a set of instructions that introduced our PC to a hardware device.
• Device drivers are not independent programs, they assists and are assisted by the operating system for the proper functioning.

System Utilities

These programs performs tasks related to the maintenance of the computer system. These are the package which are loaded into computer during time of installation of operating system. They are used to support, enhance, expand and secure existing programs and data in the computer system.

System utility mainly consists of the following functions:

( i ) Disk Compression: It increases the amount of information that can be stored on a hard disk by compressing all information stored on a hard disk. This utility works automatically and the user does not need to be aware of its existence.

( ii ) Disk Fragmentation: It detects computer files whose contents are broken across several locations on the hard disk and moves the fragments to one hard disk and moves the fragments to one location to increase efficiency. It can be used to rearrange files and unused space on your hard disk.

( iii ) Back Utilities: It can make a copy of all information stored on a disk and restore either the entire disk or selected files.

( iv ) Disk Cleaners: It is used to find files that have not been used for a long time. This utility also serves to increase the speed of a slow computer.

( v ) Anti-Virus: It is the utility which is used to scan computer for viruses and prevent the computer system files from being corrupt.

Computer Knowledge: Microsoft Excel and Its Components for Banking and Other Competitive Exams

Microsoft Excel and Its Components

Microsoft Excel

An electronic spreadsheet is used for analysing, sharing and managing information for accounting purpose performing mathematical calculations, budgeting, building, etc. A spreadsheet is a matrix of rows and columns similar to an accounting ledger. The spreadsheet program also  provides tools for creating graphs, inserting pictures and chart, analysing the data etc.

Basics of Spreadsheet

MS-Excel allows creation of spreadsheets. The basic terms of spreadsheet are:

A spreadsheet is a software tool that lets one enter, calculate, manipulate and analyse set of numbers. The intersection of each row and column is called cell. A cell is an individual container for data. It may hold Microsoft-Excel (MS-Excel), Coral Quattro Pro, Snowball, Lotus-1-2-3, Apple Numbers are some of the spreadsheet software.

To Start MS-Excel

MS-Excel is a full menu-driven software and the commands are available as icons in various tabs and groups. To start MS-Excel software, we need to Click

Start → All Programs → Microsoft Office → Microsoft Office Excel

Important Point to Remember in Microsoft Excel

• Number (Constants)
• Formulas (Mathematical equation)
• Text ( Labels)
  
• An array of cells is called a sheet or worksheet. A worksheet holds information presented in tabular row and column format with text that labels the data. 
• A workbook is a document that contains one or more worksheet.
• A row is given a number that identifies it, starts from 1,2,3,4,5............
• A column is given a letter that identifies it, starts from A......Z, AA............AZ, BA, BB...........BZ.
• A cell pointer is a cell-boundary that specifies which cell is active at that moment.
• A formula is an equation that calculates the value to be displayed. A formula must begin with equal to (=) sign.
• A cell address is used to specified the interesting of row and column of the letter and number on worksheet.

Components of Microsoft Excel

The Office Logo Button: It is at the top left corner contains many commands for the document such as New, Open, Save, Save as, Print and Close.

The Ribbon: It consists of panel of commands which are organised into a set of tabs.

Tabs: It contains the commands such as Home, Insert, Page Layout, Formulas, Data, Review, View etc as well as any additional command that you may need.

Status Bar: It displays information about the currently active worksheet. It includes page number, view shortcuts, zoom slider, etc.,

Formula Bar: It is located beneath the Ribbon. It is used to enter and edit worksheet data. It includes

• Name box: It displays the all reference or column and row location of the active cell.
• Functions: These are predefined formulas that perform calculations by using specific values, called arguments.

Clipboard: A clipboard group contains the cut, copy and paste commands.

Alignment: It is used to change alignment of the text in the cells- vertical, horizontal alignment, indentation, wrap the text, shrink it to fit within the cell and merge multiple cells.

Tables: It is used to define a range of cell as a table for easy filtering and storing and create a pivote table or chart to arrange and summarise the data.

Function Library: It contains a library of functions (Ex:- mathematical, logical, trigonometric etc), such as AND, IF, LOOKUP, AVG, DATE etc.

Formula Addressing: The formula can have relative addressing, absolute addressing and mixed addressing.

• Relative Addressing: It repeat the same formula for many difficult cells, use the copy and paste command.
• Absolute Address: to keep a certain position that is not relative to the new cell location use absolute positioning. 
• Mixed Address: It is used to keep some part relative and some absolute.

The Macros: It is used to define a sequence of actions to perform on a document or multiple documents that can be executed again and again.

Computer Knowledge: Microsoft Word and Its Components for Bank and Other Competitive Exams

Microsoft Word and Its Components

Introduction to Microsoft Word:

MS-Word is a word processing application and is one of the most important and widely used application found on computer. Word processing software is mainly used for the creation of text based documents. It provides tools for composing, editing, formatting and printing of documents smaller than 45k. The document can be a poster, report, letter, brochure, web page, newsletters, etc.,

Ex:- Wordstar, Easy Word, Note Pad for Windows.

Start MS-Word:

To start MS-Word software: We need to Click Start→ All Program → Microsoft Office → Microsoft Office Word.

Components of Microsoft Word:

Title Bar: It is shows the name of the application and name of the file. It consists of three buttons that is

• Minimise (reduces the window but word still active)
• Restore (bring word window to the maximum original size)
• Close button (bring us out of word)

Standard Tool Bar: It displays the symbol for the common operation like open, print, save etc.

Formatting Tool Bar: It displays the options which can be used to format our document like font type, size of the font, bold/underline, italicised, bullets, alingment of the text etc.

Ribbon: It is a set of tools and commands across the top of the screen. It consists of a panel of commands which are organised into a set of tabs.

Tabs: On the ribbon, it contains the buttons needed to edit characters, text and layout.

• Home Tab: It consists of :

                                     Clipboard: (cut, copy, paste)

                                     Font: (size, colour, bold, italic/underline)

                                     Paragraph: (bullets/numbering, indent)

                                     Style, Editing: (find and replace)

Insert Tab: IT consists of Pages (cover page, bland page, page break), illustrations (picture, clip art, shapes, small art, chart), links (hyper link), head and footer, page number, text (text box, data and time, object).

• Page Layout Tab: It consists of themes, page set-up, page background, paragraph.
• Review Tab: It consists of spelling and grammar, thesaurus, translate, compare and protect document.
• View Tab: IT consists of print layout, full screen layout, macros, split etc.

Ruler: It appears on the top of the document window. It allows to format the horizontal or vertical alignment of text in a document.

There are two types of rulers

• Horizontal Ruler: It indicates the width of the document and is used to set left and right margin.
• Vertical Ruler: It indicates the height of the document and is used to set top and bottom margins.

Status Bar: It displays the information such as page number, current page, current template, column number and line number etc.

Work Area: It is the rectangular area of the document window, you use to type the text. It is also called as workspace.

Cursor: It is also called insertion pointer. It denotes the place where text, graphics or any other item would be placed when you type, overwrite or insert them.