Internet & E-Mail notes for competitive exams — protocols, WWW, email parts & key terms with quick revision tables. SSC, Bank, Railway ready.
Table of Contents
What is Internet?
Internet stands for Interconnected Network. It is a global network of networks that connects millions of computers/devices worldwide, allowing them to share data and communicate using a common set of rules called protocols.
The Internet works on the principle of Client-Server architecture.
History (Important Facts):
| Fact | Detail |
|---|---|
| Origin | ARPANET (Advanced Research Projects Agency Network), developed by US Department of Defense |
| Year | 1969 |
| Term “Internet” first used | 1974 |
| Father of the Internet | Vint Cerf |
| Inventor of World Wide Web (WWW) | Tim Berners-Lee (1989) |
Internet vs Intranet vs Extranet
| Term | Meaning |
|---|---|
| Internet | Public, global network accessible to everyone |
| Intranet | Private network used within a single organization |
| Extranet | Extended intranet that allows limited access to outside users (e.g., vendors, clients) |
World Wide Web (WWW)
WWW is a system of interlinked documents/web pages accessed via the Internet using a web browser.
⚠️ Note: Internet ≠ WWW. Internet is the network/infrastructure; WWW is a service that runs on the Internet.
Key Terms:
| Term | Meaning |
|---|---|
| Website | Collection of related web pages |
| Web Page | A single document on the web |
| Web Browser | Software used to access websites (e.g., Chrome, Firefox, Edge, Safari) |
| URL | Uniform Resource Locator — address of a web page |
| HTTP | HyperText Transfer Protocol — transfers web pages |
| HTTPS | HTTP Secure — encrypted/secure version of HTTP |
| HTML | HyperText Markup Language — used to create web pages |
| Hyperlink | A clickable link that connects to another page/resource |
| Search Engine | Tool to search information on the web (Google, Bing, Yahoo) |
| ISP | Internet Service Provider — company that provides Internet access (e.g., Jio, Airtel, BSNL) |
Important Internet Protocols
| Protocol | Full Form | Use |
|---|---|---|
| HTTP/HTTPS | HyperText Transfer Protocol (Secure) | Transfer web pages |
| FTP | File Transfer Protocol | Transfer files between computers |
| SMTP | Simple Mail Transfer Protocol | Sending emails |
| POP3 | Post Office Protocol version 3 | Receiving/downloading emails |
| IMAP | Internet Message Access Protocol | Accessing emails on server (without downloading) |
| TCP/IP | Transmission Control Protocol/Internet Protocol | Basic communication protocol of the Internet |
| VoIP | Voice over Internet Protocol | Voice calls over the Internet |
| Wi-Fi | Wireless Fidelity | Wireless local networking |
Domain Names & IP Address
| Term | Meaning |
|---|---|
| IP Address | Unique numeric address assigned to every device on a network |
| Domain Name | Human-readable name for a website (e.g., google.com) |
| DNS | Domain Name System — converts domain names into IP addresses |
Common Domain Extensions:
| Extension | Type |
|---|---|
| .com | Commercial |
| .org | Organization |
| .gov | Government |
| .edu | Education |
| .net | Network |
| .in | India (country-specific) |
What is E-Mail?
E-Mail (Electronic Mail) is a method of exchanging digital messages over the Internet between users.
First email was sent by Ray Tomlinson in 1971, who also introduced the “@” symbol in email addresses.
Structure of an Email Address:
username @ domainname . com
| |
unique mail server
name (e.g., gmail, yahoo)
Parts of an Email
| Term | Meaning |
|---|---|
| To | Primary recipient’s email address |
| Cc (Carbon Copy) | Recipients get a copy; all recipients can see each other’s addresses |
| Bcc (Blind Carbon Copy) | Recipients get a copy, but addresses are hidden from others |
| Subject | Short summary/title of the email |
| Body | Main content/message of the email |
| Attachment | File added along with the email |
| Inbox | Folder where received emails are stored |
| Outbox | Folder where emails wait before being sent |
| Sent Items | Folder storing sent emails |
| Draft | Unsent, saved emails |
| Spam/Junk | Unwanted/unsolicited emails |
| Trash | Deleted emails |
Popular Email Service Providers
- Gmail (Google)
- Yahoo Mail
- Outlook/Hotmail (Microsoft)
- Rediffmail
Important Internet-Related Terms
| Term | Meaning |
|---|---|
| Cookies | Small data files stored by websites on a user’s browser to remember preferences |
| Cache | Temporary storage of web data to load pages faster |
| Download | Transferring data from Internet to a local device |
| Upload | Transferring data from a local device to the Internet |
| Bandwidth | Amount of data transferred over a network in a given time |
| Modem | Device that converts digital signals to analog and vice versa for Internet connection |
| Router | Device that directs data packets between networks |
| Browser History | Record of websites visited |
| Bookmark/Favorite | Saved shortcut to a webpage |
| Phishing | Fraudulent attempt to obtain sensitive information via fake emails/websites |
| Malware | Malicious software designed to harm a system |
| Firewall | Security system that monitors/controls incoming and outgoing network traffic |
Quick Revision Table (Most Asked Facts)
| Fact | Answer |
|---|---|
| Full form of Internet | Interconnected Network |
| Origin/first network of Internet | ARPANET (1969) |
| Father of the Internet | Vint Cerf |
| Inventor of WWW | Tim Berners-Lee (1989) |
| First email sent by | Ray Tomlinson (1971) |
| Symbol introduced in email address | @ |
| Protocol to send emails | SMTP |
| Protocol to receive emails | POP3 |
| Protocol for secure web browsing | HTTPS |
| Converts domain name to IP address | DNS |
| Language used to create web pages | HTML |
| Hidden recipient in an email | Bcc |
| Company providing Internet access | ISP |
