This document summarizes a lecture about the Internet. It discusses how the Internet interconnects computer systems around the world using standard protocols like TCP/IP. It describes how the Internet carries a wide range of information and services, including the World Wide Web, email, and more. It also outlines some key components of the Internet like browsers, servers, and protocols. Finally, it discusses advantages of the Internet like accessibility, ease of use, and low costs.

1. Lecture No. 7: The Internet
Lecturer: Dr. Mazin Alkathiri
Department of Information Technology,
college of Applied Science,
Seiyun University
2023

2.  Internet is a system that interconnects the different computer systems across the
world.
◦ It uses the Internet protocol suite to link devices located in different corners of the world.
 The Internet system carries an extensive range of information resources and
services including World Wide Web (WWW), telephony, electronic mail, etc.
◦ It uses standard internet protocols, such as TCP/IP and HTTP, etc.
 An internal web comprises of all Hypertext Transfer Protocol (HTTP) nodes on a
private network;
◦ for example, an organization’s LAN or WAN.

3.  Accessibility: Internet is a global service and accessible to all.
 Easy to Use: The software, which is used to access the Internet
(web browser), is designed very simple.
 Interaction with Other Media: Internet service has a high
degree of interaction with other media. For example, News and other
magazine, publishing houses have extended their business with the help
of Internet services.
 Low Cost: The development and maintenance cost of Internet
service are comparatively low.

4.  Extension of Existing IT Technology: This facilitates the sharing of IT
technology by multiple users in organizations.
 Flexibility of Communication: Communication through Internet is flexible enough.
It facilitates communication through text, voice, and video too.
 Security: Internet facility has to a certain extent helped the security system both at the
individual and national level with components such as CCTV camera, etc.

5.  TCP/IP (Transmission Control Protocol/Internet Protocol)
◦ Dictates how info sent over the Internet
◦ Subprotocols then specify rules for specific types of communication
 FTP(File Transfer Protocol)
 SMTP(Simple Mail Transfer Protocol)
 POP(Post Office Protocol)
 IRC(Internet Relay Chate)

6. 6
 HyperText Transfer Protocol
◦ Specifies how web resources (like web pages) are transmitted over the
Internet
◦ It is a client-server protocol
 Request for web resources initiated by a client computer
 Web resources “managed” by server computers
 Managed means stored, organized and transmitted

7. 7
Client/Server Structure of the World Wide Web

8. 8
 A Web browser is a software (s/w) application that runs on a
device to make it work as a Web client
 Web servers: computers that run server s/w that enable them
provide files through the Web
 Web pages are stored in files that contain HTML (HyperText
Markup Language) instructions, text, images, sound, etc.

9. 9
 Host can be identified by an IP address or a Domain name
IP address: four numbers (ranging from 0 to 255)
separated by periods
Example: 104.46.104.203
Domain name
Example: www.seiyunu.edu.ye

10.  Internet Software comprises of all the tools needed for networking through
computer. Following are a few important components of the Internet Software −
 Transmission Control Protocol/ Internet Protocol (TCP/IP)
 Dialer Software
 Interment Browser

11.  Internet applications are server-based applications. Following are a few
Internet Applications −
 World Wide Web (WWW)
 Electronic mail (e-mail)
 File Transfer Protocol (FTP)
 Telnet (i.e., log-in to the computer located remotely)
 Internet Relay Chat (IRC) (Real time video chatting)