1. The Internet and Electronic mail

2. URL – Uniform Resource Locator
To transmit the information among the computers in the Internet, the protocol called HTTP (Hypertext Transfer Protocol) is used.
Further, the main service which provides the information is the World Wide Web (www).
Therefore, the information in the World Wide Web is included in web sites.
The system used to uniquely identify various resources in web sites is the Uniform Resource Locator (URL)

3. Top level domain
Eg:

4. Given below are some URL related to the field of Education.
- Ministry of Education
- National Institute of Education
- Department of Examinations
- Educational Publications Department

6. Domain name
Domain name gives an identity to all the websites which exist in the Internet.

7. How the Internet work
When a URL is entered to the browser to view a website, the request must first be translated from the readable written address into an IP address that can be routed. This translation is done by the Domain Name System (DNS).
When a request is made to connect to certain website, for example the request is first sent to the DNS server to translate into the correct IP address of The actual connection to the website is done with this IP address.
Note:
Please refer page 68 for types of protocols

8. Uploading and Downloads
The computer that distributes the resources required by the client computer is called the "server".
The activity of retrieving information from the server computers to client computers is called "downloading".
The activity of providing information from client computers to server computers is called "uploading".

9. Services of the Internet
following are some of the services of the internet;
1.World Wide Web – WWW
2.File Transfer Protocol
3.Remote Access
4. File Sharing
5. Streaming of media
6. Search Engines
7. Electronic Mail - e mail

10. 1.World Wide Web – WWW
World Wide Web is a service provided by the Internet and it is a large collection of electronic documents saved in computers all around the world connected to the internet.
Sir Tim Berners Lee is considered the father of www. A user who uses www can access web sites through a Web Browser.
A Web Browser is an application software. Following are some examples of Web Browsers.

11. Internet Browser
Internet Browser or Web browser is also another kind of application software which is use to surf the web which means it is used to view pages on the World Wide Web

12. 2.File Transfer Protocol
FTP is used to transfer large files of one computer in the Internet to another computer.
This protocol is operated on TCP/IP and used to upload files of a client computer to the Internet and to download files from server computers in the Internet.

13. 3.

14. 4. File Sharing
sharing of various files in the Internet take place often.
Example
1. When you check exam results on line, that file is accessed by a large number of clients at the same time.
2. Thousands of users can be connected to a web site at the same time

15. 5.

16. 6. Search Engines
Search Engine is a software that enables users to search the Internet using keywords.

17. 7.
A system whereby a computer user can exchange messages with other computer users (or groups of users) via a communications network.
Electronic mail-messages transmitted electronically between computers.
If you want to send something else other than text, you'll need to use an attachment.

18. cont….
To create, send, and receive messages, you need an program and an account on an Internet mail server with a domain name.
To use , a user must have an address, which you create by adding your user name to the
server's domain name, as in

19. How works

20. 8.

21. Chat
Two or more individuals connected to Internet have real-time text-based conversations by typing messages into their computer.
Groups gather to chat about various subjects. As you type, everything you type is displayed to the other members of the chat group.

22. Sample Chat Program

23. Video Conferencing
Communicate in real time with two or more people at different locations via web camera is called Video Conferencing.
Involves using video and audio signals to link participants at different and locations for a specific purpose.

24. Video Conferencing – How It works

25. Video Conferencing – Practical Situation

26. Note : Please refer page 78 and 79 for social network and cloud computing