001 - Basic of internet

Soumya Jana

Mon Feb 17 2025

What is internet?

The internet is a global network of interconnected computers and devices that communicate with each other using standardized protocols. Here's a simplified explanation of how it works:

1. Basic Structure

The internet is a network of networks. It connects millions of smaller networks, such as home networks, business networks, and government networks.

These networks are linked through physical infrastructure, including cables (fiber optics, copper), wireless signals (Wi-Fi, satellites), and routers.

2. Key Components

Devices: Computers, smartphones, servers, and other devices that send and receive data.
Routers: Devices that direct data packets between networks.
Servers: Computers that store and deliver data (e.g., websites, emails).
IP Addresses: Unique identifiers assigned to each device on the internet (e.g., 192.168.1.1 or 2001:0db8:85a3::8a2e:0370:7334).
DNS (Domain Name System): Translates human-readable domain names (e.g., google.com) into IP addresses.
Protocols: Rules and standards for data transmission (e.g., TCP/IP, HTTP, HTTPS).

3. Data Transmission

Data is broken into small packets for efficient transmission.

Each packet contains:
The source and destination IP addresses.
The data being sent.
Information for reassembling the packets at the destination.
Packets travel through multiple routers and networks to reach their destination.

4. How Communication Happens

When you type a URL (e.g., www.google.com) into your browser:

Your device uses DNS to convert the domain name into an IP address.
Your browser sends a request to the server at that IP address.
The server processes the request and sends back the requested data (e.g., a webpage).
Your browser reassembles the data and displays it.

5. Protocols and Standards

TCP/IP (Transmission Control Protocol/Internet Protocol): The foundational protocol suite for internet communication.

HTTP/HTTPS: Protocols for transferring web pages (HTTPS is secure).
SMTP/IMAP/POP: Protocols for email communication.
FTP: Protocol for file transfers.

6. Infrastructure

Undersea Cables: Fiber-optic cables laid on ocean floors to connect continents.

Data Centers: Facilities housing servers that store and process data.
ISPs (Internet Service Providers): Companies that provide internet access to users.

7. Security and Encryption

Data is often encrypted (e.g., HTTPS, VPNs) to protect it from interception.

Firewalls and other security measures help prevent unauthorized access.

8. Global Connectivity

The internet is decentralized, meaning no single entity controls it.
Organizations like ICANN (Internet Corporation for Assigned Names and Numbers) manage domain names and IP addresses.

In summary, the internet works by connecting devices and networks worldwide, using standardized protocols to transmit data efficiently and securely. It relies on a combination of hardware (cables, routers, servers) and software (protocols, DNS) to function.