ICT teacher handbook/What is internet and web

Internet

If you want information about your bank balance, you can connect to your bank's computer from home and get the information that you want. There are many such computers in different organisations giving us different types of information. These computers are connected to one another, their network is called the Internet. The Internet is thus a physical network of millions of computers across the world, each of which has a unique identifier. Some of these computers act as 'servers', they store data which can be accessed by other computers. The millions of computers which are part of the Internet, is like a huge library with information on almost any issue. Apart from information, many of these computers also have applications or web tools, such as search engine, maps, translation, which have different purposes. The 'web-sites' we visit are nothing but folders of computers connected to the internet.

These computers communicate or share data with one another using the protocol called the TCP-IP, (transmission control protocol/internet protocol). As the name suggests, TCP/IP is the combination of TCP and IP protocols working together. Under TCP/IP each file being transported across the Internet is broken into smaller parts called "packets" by the server. Each packet is assigned an IP (Internet protocol) address of the computer it has to travel to. As the packet moves through the global network it is "switched" by a number of servers toward its destination, the requesting computer or "client" computer. These packets do not usually travel together on the Internet. Packets from the same file may travel via different paths through different servers, but toward the same destination. This “splitting into packets” technology allows us to use Internet most efficiently. It means parts of a file can be shared across a number of phone lines instead of having to find one phone line to put a large file into. It is also hard to break the network, as the data will be routed around the trouble spot. In this respect TCP/IP can be likened to a group of cars which need to go to the same destination, but instead of all of them going on one road (which may be busy), each car can select a different road out of thousands of roads available. By picking the roads with least traffic, all cars can reach the destination in overall least time. The power of the internet to rapidly move information from any computer to any computer is because of the TCP/IP protocol.

The TCP/IP protocol was invented by Vincent Van Cerf, Robert Kahn and Louis Pouzin.

World Wide Web

World wide web (www) is an application on the Internet, which was invented by Tim Berners Lee. The www allows computers to access the Internet in the form of a web page, using an application called the Web Browser. There are millions of pages of shared information on the computers in the network, created by many people and organizations, in the form of 'web pages' accessed using a software application called a 'web browser'.

This information network, called the World Wide Web, consists of web sites. A web site is a collection of related web pages. Web pages are identified by means of a URL (uniform resource locater), which is treated as the website address, usually beginning with “http://” (HTTP stands for hypertext transfer protocol, which is the method used for transferring web page information from the server to your computer. We connect to the Internet using a web browser and the browser opens one web page. This web page has links to other web sites / web pages which we can visit by clicking on the links. Each of the subsequent pages will also have many links which we can click on. Thus we can visualise the world wide web as a huge mansion with many rooms, each room having many doors. When we enter a room (open a web page), we can access the resources in that room. We can also go from that room to other rooms through the several doors that this room has (go from one web page to another web page by clicking on any of the links on the page we are in). The new room also would have many doors. Thus we can go through the mansion from room to room (web page to web page) through the door (web link) in each room. Thus though the entire web is very huge, we only access it one page at a time. We can connect to the web and go from web page to web page using a software called the web browser. Web browsers allow a user to quickly and easily get information provided on many web pages at many websites.

Initially the access to the www was only for downloading, this was called Web 1.0. Subsequently the second generation of www was evolved, called Web 2.0. , where ordinary users can create their own materials and publish on the Internet, using software tools like blog or wiki. A blog is like a e-journal and teachers can create their own e-journals for reflective practice using software tools such such as WordPress

We have moved further along now to collaborative creation of web pages, through online collaboration platforms. Now more and more processing can be done on the Internet, where the data, results and analysis is stored the Internet and we can operate/ add/ access through various web based applications. This is called Cloud Computing.