Information Technology

INFORMATION

AND COMMUNICATION TECHNOLOGY (ICT)

by ( Dr. Yasir Zafar Khan)

((((

Information Technology

Communication Technology

Computation

Technology

 Information Technology: Is the process of Creating, Gathering, receiving, Storing, Receiving &

Delivering of Information from one place to another.



Computation Technology: The process of utilizing computation technology to complete a task. Computing may involve computer hardware and/or software, but must involve some form of a computer system.

Most individuals use some form of computing

every day whether they realize it or not.

Information Communication Technology

Communication Technology

Information

Technology

ICT

 ICT is used as a general term for all kinds of technologies which enable users to Create,Access & Manipulate information.

 ICT is a combination of Information

technology and Communication technology.

ICT Uses

 Increases Networking Opportunities : IT help connect to other schools, as well as individual within those schools to one another.

 Provide Distance learning : with the advent of ICTs, learning has become web-based. As a result, ICT have started to replace correspondence schools.

 Supplement Traditional Learning: One of the most common uses of ICT in Education involves student using s/w programs

i.e MS-word.



ADVANTAGES



Increased access to resource: 24 x 7



Interactive Learning Experience:AudioVideos,

& other interactive media.



Student-Centered Learning: systematic Lesson plan.



DISADVANTAGES :



High Cost : Updating Infrastructure, training teachers &

developing quality course material.



Teachers Training: Unfamiliar with ICTs in the classroom & are resistant to incorporating such technologies.



Availability of Internet connectivity

Computer Networks & Internet

 A Computer network consist of two or more computers that are connected to each other using cables & other network devices that handle the flow of data.

 Connectivity : is a concept related to using computer network to link people & resources.

 Communication Switching : networks use two common methods of commendation switching to transfer data : 1) Circuit 2) Packet

 Circuit Switching : The switches create a single, unbroken path between devices that want to communicate.

 Packet Switching : Data are transmitted in short packets.

 A typical upper limit on packet length is 1 kilobyte.

 It is longer message to send, the message is broken up into a series of packets.

 The Internet is a packet switching network

COMMUNICATION CHANNELS

 Communication channels actually carry the data from one computer to another.

 There are two categories of communication channels.

Physical Connections : physical connections use a solid medium to connect sending & receiving devices.

 These connections include telephone lines :

a)Twisted pair b) Coaxial cable c) Fiber-optical cable.

Wireless Connections: wireless connections do not use a solid substance to connect sending & receiving devices.

They use the air itself.

a) Infrared (line-of-sight) b) Satellite c) RADAR d) Microwave (Bluetooth) Straight line through air

e) Broadcast radioWi-Fi (wireless fidelity)

DATA TRANSMISSION

BANDWIDTH : is a measurement of the width or capacity of the communication channel.

 How much information can move across the communication channel in a given amount of time.

VOICE BAND : also known as low bandwidth, is used for standard telephone communication.

• Microcomputer with standard modems & dial up service use this bandwidth .

MEDIUM BAND: used in special leased lines to connect mini computers & mainframe as well as transmit data over long distances:

Two mid band technologies are :

1) Asymmetrical Digital Subscriber Line (ADSL) 2) Integrated Service Digital Network (ISDN)

BROADBAND: is the bandwidth used for high-capacity transmission.

• Microcomputer with DSL ,Cable & Satellite connections as well other more high-speed devices use this bandwidth.

TYPES OF COMPUTER NETWORKS



Broadly Computer network divided into three categories:



LAN (LOCAL AREA NETWORK) : A computer network that spans a relatively small area. Most of LAN‟s are confined to as single building or group of buildings.



However one LAN connected to other LANs over any distance via telephone lines & radio waves.



Most LANs connected workstations & PC‟s. Each node in a LAN has its own CPU with which it executes program. But it also able to access data and devices anywhere on the LAN.



E.g. Ethernet being the most common for PCs.

AppleTalk network system for Macintosh computers.



MAN ( Metropolitan Area Network) : Man span distance up to 100 miles.



These network are frequently used as links between office buildings that are located throughout the city.



MAN is typically not owned by a single organization. Rather, it is either owned by group of organization who jointly operate the network or by a single network service provider.



WAN (Wide Area Network) : are countrywide & worldwide network.



These network provide access to regional service (MAN) providers & typically span distances greater than 100 miles.



They used Microwave & Satellites to reach users over long distances.



The Primary difference between LAN, Man & WAN is the

geographical range.

INTERNET



INTERNET : It is a network of computers spread across nations & which is made possible by reliable telecommunication.



It‟s a network of network



The Internet is not a single, unified network & so it is not surprising that it is not controlled by a single body.



Groups exist to carry out central management functions for the internet:



INTERNET SOCIETY (ISOC): This professional society is concerned with the growth & evolution of the worldwide internet.



With the way the internet can be used & with the social,

political & technical issues.

INTERNET SOCIETY SUB GROUPS ARE :



INTERNET ARCHITECTURE BOARD (IAB) : responsibility for the technical management & direction of the Internet. Its also responsible for overall architectural considerations in the Internet.

 INTERNET ENGINEERING STEERING GROUP (IESG)

 INTERNET ENGINEERING TASK FORCE

:



The protocol engineering and development arm of the internet.



The IETF is divided into eight functional areas such as :

APPLICATIONS MANAGEMENT ROUTING

NETWORK SECURITY

OPERATIONAL REQUIREMENT TRANSPORT

INTERNET. USER SERVICE

APPLICATION AREAS OF INTERNET

S.R

no. APPLICATION PROTOCOL PURPOSE

1. World wide Web (WWW)

W3Constorium

Hypertext Transport Protocol (HTTP)

Offers access to hypertext documents, executable programs

& other Internet resources .

2.

E-mail

Alllows the transmission of text messages & binary attachments across the Internet

3.

File Transfer

Enables files to be upload &

download across the internet

4.

Chat

5.

UseNetgroups

Discussions forums where users can asynchronously post messages

& read messages posted others.

6.

Interactive text oriented

communications

Remote login Session

(Telnet)

Offers users the capability of running programs remotely

& facilitates remote admin.

7.

Network management systems

Simple Network management Protocol (SNM)

Allows for remote & local management of items on the network including servers,

workstations, routers, switches &

other managed devices.

8.

Library

Information servers (WAIS)

Allows users of computers to share information using a

common computer to computer protocol.

9.

Search Engines

& Veronica

Use to search information, database

INTERNET PROTOCOL

 A protocol is defined as a set of rules governing the exchange of data between two entities.

 An IP Address is a number that a represents a device uniquely on the Internet or on your company‟s intranet.This number is binary one.

 Normally written as four decimal numbers. (192.168.1.1.)

 Depending on the size of the network, the IP-based networks are divided into three classes:

 Class A ( 1.0.0.0 to 126.0.0.0), support 16 million plus connection

 Class B (128.0.0.0 to 191.0.0.0), support 65000 nodes

 Class C ( 192.0.0.0 to 223.0.0.0) support 254 nodes

 Class D & E are primarily used for experimental purposes.

 The standard protocol for the internet isTCP/IP (Transmission Control Protocol/Internet Protocol.

 Essential features of protocol involve

 1) Identification 2) Reformatting

 The Current version of IP is IPv4 (32 bits addressing mode)

 Next Generation IP is IPv6 (128 bits addressing mode)

DOMAIN NAME SYSTEM & UNIFORM RESOURCE LOCATOR



DOMAIN NAME SYSTEM (

The unique name of a collection of computers connected to the networks such as the internet.

The DNS is hierarchical, consisting of domain, sub-domains, sites & hosts.

Top level domains are :

1) com (commercial) 2) net (Networks)

3) edu (Educational 4) jp (Japan)

5) us (United states) 6) de (US Military) 7) org (Organizational) 8) gov (Government) 9) ru ( Russian Federation) 10) cn ( China)

11) in (India)

e.g. http//:www.indiarail.gov.in, http//:amu.ac.in

http//:www.flipkart.com, http//:www.islam.net,

UNIFORM RECOURSE LOCATOR (URL’S):

 A URL identifies a particular Internet recourse. Url‟s represent a standardized addressing scheme for internet resources & help the users to locate these resources by indicating exactly where they are.

 URL‟s consists of letters, numbers & punctuations.

 The basic structure of URL is hierarchical & moves from left to right as : protocol://server-name.domain-name.top-level-

domain:port/directory/filename

E.g.

http//:www.alexisleon.com,

http://www.banks.com/login/password.htm /

 The above URL consist of:

❖ Protocol : http

❖ Host computer name : www

❖ Domain name : banks

❖ Domain type : com

❖ Path : /login

❖ File name : password.html

ELEMENTS OF ABSOLUTE AND RELATIVE URL :

 An Absolute URL is independent or free from any relationship.

 It specifies the exact location of a file or directory on the internet.

 It is easy to transfer a web site from one domain name to another, you need not to update each link on each page.

 For example: http://www.developers.com/images/hardware.gif

 A Relative URL is targeted to a file or directory in relation to the present file or directory.

 If the web site has several sections and the files and web pages for each section have been segregated into different directories. This helps in keeping things organized and uncluttered on the web site.

 The relative URLs are shorter than absolute URLs and hence the file size of the web page would reduce, if you use the former.

 For example:The <img> tag for this image display will be as follows:

 Using a Relative URLin an <IMG> tag

 <img src=”../images/hardware.gif ” width=”...” height=”...” />

ORGANIZATIONAL INTERNET



Intranet: An intranet is a private network within an orgnization that resembles the internet.



Organization use intranet to provide information to their employees.



Employees benefit information, internal job openings, & much more.

Employees find surfing their organizational intranet to be easy as intuitive as surfing the internet.



Extranet : A n Extranet is a private network that connects more than one orgnization.



Firewall : Organizations have to be very careful to protect their information system.



A Firewall is a system designed to protect an organization's network

against external threats.

WORLD WIDE WEB (WWW)



The World Wide Web (WWW) is an internet based service, which uses common set of rules known as Protocols, to distribute documents across the Internet in a standard way.



The World Wide Web, or „Web‟ is a part of the Internet. The Web is viewed through web browser softwares such as Google Chrome, Internet Explorer, Mozilla Firefox etc.



The www is one of the newest internet service.The www allows you to combine text, graphics, animation, audio & video to make a document a learning experience.



Links within www documents can take quickly to other related document.



The www is an information system designed specifically with ease of

use & document interchange in mind.



Today thousands of web pages/websites are added to the WWW every hour.



HTML was based on subset of the Standard Generalized Markup language (SGML).



To transfer HTML document to remote sites (HTTP) was used.



HTTP offers to moving from document to document and indexing within documents.



Few web development languages are



HTML (hypertext mark up language) (Latest version is 5.0)



DHTML (Dynamic HTML)



XML (Extendable Markup Language)



CFML (Cold Fusion Markup Langauge)



Asp. Net Java script. VBScript

DIFFERENCE BETWEEN INTERNET AND WWW



The Internet is known as “interconnection of computer networks”



The World Wide Web, or “Web” for short, or simply Web, is a massive collection of digital pages to access information over the Internet.



The Web uses the HTTP protocol, to transmit data and allows applications to communicate in order to exchange business logic.



The Web also uses browsers, such as Internet Explorer , Firefox, to access Web documents called Web pages that are linked to each other via hyperlinks.



Web documents also contain graphics, sounds, text and video.

SEARCH ENGINES

 Search engines are the programs which are needed to extract the information from the internet.

 Web search engines work with the help of two programs,

 Spider which fetches as many documents as possible.

 Indexer, reads the documents and creates an index based on the words contained in each document.

 Each search engine uses an algorithm to create its indices

such that, only related results for specified keywords is

stored and returns a list of the documents where the

keywords were found.

HOW SEARCH ENGINE WORKS

 WEB CRAWLING: Web search engines work by storing information about many web pages.

 These pages are retrieved by the program known as Web crawler - which follows every link on the site.

Web crawler may also be called a Web spider.

 INDEXING: Indexing also known as web indexing, it stores data to facilitate fast and accurate information retrieval.

 SEARCHING: A web search query fetches the result

from the web search engine entered by the user to meet

his information needs.

WEB SERVERS

• The primary job of a web server is to deliver web pages to clients.

• The communication between the client node and server node takes place using the HypertextTransfer Protocol (HTTP).

• The delivered web pages include images, style sheets and scripts in

addition to text content.

SERVER SOFTWARE



A web server commonly known as HTTP server or application server is a program that serves content using the HTTP protocol.



This content is generally in the form of HTML documents, images, and other web resources, but can include any type of file.



The content served by the web server can be pre-existing (static content) or generated on the fly (dynamic content).



Apache web server - the HTTP web server



ApacheTomcat



Lighttpd



Jigsaw

SERVICES PROVIDED BY THE SERVERS



Today many services are being provided by the Web Server.

Many of the servers are based on Cloud computing which is popular amongst the researchers, scientists & entrepreneurs.



Cloud Computing is distributed computing over a network, and has the ability to run a program or application on many connected computers at the same time.



It is used, where various computing concepts that involve a large

number of computers are connected via real-time communication

network such as the Internet.

VARIOUS SERVICES PROVIDED BY THE WEB SERVER

 Cost Efficient:

 Resource Sharing:

 Data Sharing:

 Backup and Recovery:

TYPES OF SERVERS



MAIL SERVER: Mail Servers provides a centrally-located pool of disk space for network users to store and share various documents in the form of emails.



APPLICATION SERVER: An application server acts as a set of components accessible to the software developer through an API defined by the platform itself.



FILE TRANSFER PROTOCOL (FTP) SERVER: FTP uses separate control and data connections between the client and the server.



DATABASE SERVER: A database server is a computer program that provides database services to other computer programs or computers using client-server model.



DOMAIN NAME SYSTEM (DNS) SERVER: A name server is a computer server that hosts a network service for providing responses to queries

 .

WEB SITE

 The collection of web pages on the World Wide Web that is accessed by its own Internet address is called a Web site.

 Web site is a collection of relatedWeb pages.

 Each Web site contains a home page and contains other additional pages.

 Each Web site is owned and updated by an individual, company, or an organization.

 Web is a dynamically moving and changing entity,

today web sites generally change on a daily or even

hourly basis.

HOW WEBSITE IS DIFFERENT FROM PORTAL?



WEB PORTAL is a medium by which users access the resources.



While a website is a destination in itself.



Portals and websites are distinct entities which are linked together, but they should not replace each other.



A WEBSITE is also a portal, if it broadcast information from different independent resources where as Web Portal refers to a website or services that provide varied resources and services such as email, forums, search engines and online shopping malls.



Some of the web portals are AOL, iGoogle,Yahoo and even more.



A website refers to a location or a domain name hosted on a server which is accessible via internet. It is a collection of web pages, images, videos which are addressed relative to a Uniform Resource Locator (URL).



Websites provide content from independent resources to specific

audience.

COMPONENTS OF WEBSITE

 CONTENTS OF A WEB PAGE:

 WEBSITE GRAPHICS:

 HEADING OF THE SITE

 EFFECTIVE COLOUR CONTRAST

 SCREEN RESOLUTION

 GOOD VISUAL DESIGN

 SCREEN RESOLUTION

 INSERT MEANINGFUL RAPHICS

 SIMPLICITY:

 RELEVANT CONTENT

 NAVIGATION:

 RELEVANT

 MINIMAL SCROLL

 CONSISTENT LAYOUT

 CROSS-PLATFORM/BROWSER COMPATIBILITY

ELEMENTS OF WEBSITE

CONSTRUCTION OF WEBSITE



Steps to build a Website



Step 1: Hosting



Step 2:Domain Name



Step 3: Plan Your Website

Step 4: Build Your Website Page by Page



Step 5: Publish Your Website



Step 6: Promote Your Website



Step 7: Maintain Your Website

SOFTWARE USED TO CREATE WEBSITE

CoffeeCup Free HTML Editor Notepad++

PageBreeze Firebug

Bluefish Editor Brackets

KompoZer OpenBEXI GIMP

BlueGriffon

WEBPAGE

 A Web page also known as Electronic Page

 Is a part of the World Wide Web.

 It is just like a page in a book.

 The basic unit of every Web site or document on the Web is a Web page containing the information.

 A Web page can contain an article, or a single

paragraph, photographs, and it is usually a

combination of text and graphics.

STATIC AND DYNAMIC AREAS

 A static web page often called a flat page or stationary page, is a web page that is delivered to the user exactly as stored.

 A static web page displays the same information for all users, such versions are available and the server is configured to do so.

 Such web pages are suitable for the contents that never or rarely need to be updated.

 A dynamic web page is a web page which needs to be

refreshed every time whenever it opens in any of the

web browsers to display the updated content of the

site .

DIFFERENCE BETWEEN WEBPAGE AND WEBSITE

A web page is one single page of

information, while a website is made

up of a number of different web

pages connected by links known as

Hyperlinks .

WEB BROWSER



A browser is a software that lets you view web pages, graphics and the online content.



Browser software is specifically designed to convert HTML and XML into readable documents.



The most popular web browsers are: Google Chrome, Firefox, Internet Explorer, Safari, Opera and UC Browser.

SECURE SOCKET LAYER (SSL)



The Secure Sockets Layer (SSL) is a protocol, uses Hypertext Transfer Protocol (HTTP) and Transport Control Protocol (TCP) for managing the security of a message transmission on the Internet.

The “sockets” term refers to the sockets method of passing data

back and forth between a client and a server program in a network

or between program layers in the same computer..

VARIOUS WEB BROWSERS

 Google Chrome Mozilla Firefox

 Safari Opera

 Maxthon Mozilla Firefox

 Safari Opera Maxthon

 Internet Explorer Netscape Navigator

 Avant Browser YouTube Browser

 UC Browser

BLOGS



A blog, short for „web log‟ is a modern online writer‟s column.



A blog is a web site like any other, but it is intended to offer personal opinions of people on their hobbies, interests, commentaries, photo blogs, etc.



blogs started out as online personal diaries, but in a technology- driven world, now they have also been taken up by businesses as an informal method of communicating with customers and clients.



Blogs can also be used for commercial purposes, too. Absolutely anyone can start a blog, but some people make reasonable incomes by selling advertising on their blog pages. Social network companies also realise how popular blogs are and many offer free blog space

(e.g. MySpace).



Another feature of popularising a blog is the ability of visitors to add

comments to the stories.

TWO WAYS FOR STARTING YOUR OWN BLOG:

 FREE BLOG HOSTING:

 You do not need a server to start your own blog.

 There are plenty of free, open source blogging software you can install.

For example WordPress and Moveable Type .

 PAID BLOGGING:

 Another way is when a company provides you a

limited amount of space or a column on their website

and the blogger has to pay for the same till the time he

is using the available space.

TYPES OF BLOGS



There are millions of blogs on the Web. But they are categorised into these types:



Personal blogs



News and views



Company blogs



Micro blogs BLOGGERS

 A person who writes a blog is simply known as a blogger.

 Associating this to social networking websites allows

you to get viewers and readers who would then

promote these amongst other people.



1. We can work on blog anytime and anywhere in the world.



2. You are your own employee. When blogging, you can blog any time you want to whenever you think of something that is relevant to your blog.



3. As a blogger, you are flexible and can choose to write about anything in the world as long as it benefits you.



4. Very quick and easy to set up, do not need much technical knowledge.



5. Easy and quick to update or add new posts.



People can leave comments on your blog and you can comment on

other persons’ blogs, too

DISADVANTAGES OF BLOGGING

 1.

You need to be patient because you don‟t start earning in a single day.

 2. Blogging is time-consuming. You need to be disciplined.

 3. You need to be very active as a blogger so that people can read your blog posts.

 4. As you know the public to everyone, you need to put a check on your language.

 5. There are many very dull blogs around. You may have

to look at many before you find some worth reading.

NETWORK TERMS



NODE : Any device that is connected to a network. It could be computer, printer or data storage device.



CLIENT : A node that requests & uses resources available from other nodes. (Micro computer).



Server :A node that shares resources with other nodes.



HUB: The Centre or central node for other nodes. This device can be server or simply connection point for cables from other nodes.



NIC (Network Interface Card) Located with the system unit that connect the computer to a network. Also know as LAN Adopter



NIOS (Network Operating Systems): control & coordinates

the activities of all computer & other devices on a network.

 HOST COMPUTER : large centralized computer, usually a mini computer.

 NETWORK ADMIN.: A computer specialist responsible for efficient network operations & implementation of new network.

 MODEM: (Modulation & Demodulation) : Modulation- process to converting from digital to analog signal.

 DEMODULATION - process to converting from analog to digital signal.

 Four types of Modems are : 1)External 2) Internal

3) PC Card modem 4) Wireless Modem

 WEB COOKIES : Cookies have become a valuable way to keep track of visitor‟s movement on your site.

 BAUD RATE : A unit used to measure the number of data bits a modem can transfer in one second. Information measures in bits.

 Higher baud modems can send & receive more signals in a second.

Thank You