🌐 INTERNET – Complete Notes
(Home Academy | Exam-Oriented for JKSSB, SSC, Bank, UGC NET)
🔹 1. Meaning of Internet
The Internet is a global network of interconnected computers that communicate using standard protocols like TCP/IP. It is known as the “Network of Networks.”
🔹 2. History of Internet
| Year | Development |
|---|---|
| 1969 | ARPANET started |
| 1971 | First email sent by Ray Tomlinson |
| 1983 | TCP/IP adopted |
| 1989 | WWW proposed by Tim Berners-Lee |
| 1991 | World Wide Web launched |
| 1995 | Internet introduced in India (VSNL) |
Important exam point: Internet was developed before the World Wide Web.
🔹 3. Internet vs World Wide Web (WWW)
| Internet | WWW |
|---|---|
| Network infrastructure | Information system |
| Started in 1969 | Started in 1991 |
| Uses TCP/IP | Uses HTTP/HTTPS |
| Hardware and software system | Web pages and websites |
🔹 4. Basic Requirements for Internet
A computer or smartphone is required along with a modem or router. An Internet Service Provider (ISP) provides connectivity. A web browser is necessary to access websites.
🔹 5. Internet Service Provider (ISP)
An ISP provides internet access to users. Examples in India include Jio, Airtel, and BSNL.
🔹 6. Important Internet Protocols
| Protocol | Full Form | Use |
|---|---|---|
| HTTP | HyperText Transfer Protocol | Web browsing |
| HTTPS | HyperText Transfer Protocol Secure | Secure browsing |
| FTP | File Transfer Protocol | File transfer |
| SMTP | Simple Mail Transfer Protocol | Sending emails |
| POP3 | Post Office Protocol Version 3 | Receiving emails |
| IMAP | Internet Message Access Protocol | Receiving emails |
🔹 7. IP Address
An IP address is a unique numerical address assigned to each device connected to the internet. Example: 192.168.1.1. IPv4 is 32-bit while IPv6 is 128-bit.
🔹 8. Domain Name System (DNS)
DNS converts domain names into IP addresses. For example, google.com is translated into its numerical IP address through DNS.
🔹 9. Web Browser
A web browser is software used to access websites. Examples include Google Chrome, Mozilla Firefox, and Microsoft Edge.
Browser and search engine are not the same.
🔹 10. Search Engine
A search engine is used to find information on the internet. Examples include Google, Yahoo, and Bing.
🔹 11. Types of Internet Connections
The main types of internet connections are Dial-up, Broadband, Wi-Fi, Fiber connection, and Mobile data such as 4G and 5G.
🔹 12. Advantages of Internet
The internet enables fast communication, online education, e-commerce, e-governance services, and social networking platforms.
🔹 13. Disadvantages of Internet
The internet can lead to cybercrime, hacking, phishing attacks, and addiction if not used properly.
🎯 Most Important Exam Points
Internet started in 1969 under ARPANET.
World Wide Web was invented by Tim Berners-Lee.
Email was invented in 1971.
HTTP is used for web browsing.
SMTP is used for sending emails.
POP3 and IMAP are used for receiving emails.
An IP address uniquely identifies a device on the internet.
📘 Practice MCQs
Internet started in:
A) 1965
B) 1969
C) 1975
D) 1989
Answer: B) 1969
WWW was invented by:
A) Ray Tomlinson
B) Bill Gates
C) Tim Berners-Lee
D) Vint Cerf
Answer: C) Tim Berners-Lee
Which protocol is used for web browsing?
A) FTP
B) HTTP
C) SMTP
D) POP3
Answer: B) HTTP
Full form of ISP:
A) Internet System Protocol
B) Internal Service Provider
C) Internet Service Provider
D) Integrated Service Protocol
Answer: C) Internet Service Provider