How the Internet works

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HTTP

HTTP stands for Hyper Text Transfer Protocol. It is used to fetch documents such as html documents. HTTP is the foundation of data communication on the World Wide Web, enabling the transfer of information between web servers and clients (browsers).

Characterstics of HTTP

• Stateless:

  • The server has no memory of previous interactions with the same client.

• Client-Server Architecture:

  • Clients requests to servers.

  • Servers process requests and send responses.

• Flexible:

  • Supports various methods (GET, POST, PUT, DELETE, etc.) for different actions.

  • Allows for customization with headers and parameters.

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How HTTP works

HTTP (Hypertext Transfer Protocol) is a stateless communication protocol that operates on a client-server model. See the steps :

1. First, the user makes a request. For example, the user requests the URL: https://kads.in.

2. This request is sent to the server hosting the website.

3. If everything is valid and the requested resource is available, the server processes the request and sends a response back to the user.

4. If successful, the server responds with the html page along with a status code like 200 OK.

5. If there’s an issue, the server returns an error response with a status code like 404 Not Found.

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User Agent

A User agent is basically a software who sends request to the server.

Examples:

Chrome, Mozila, Safari etc.

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TCP (Transmission Control Protocol)

TCP is a reliable, connection-oriented communication protocol used for ensuring accurate and ordered data delivery over a network.

• Key Features

  • Connection setup is required.

  • Reliable data transfer with error checking and correction.

  • No data lost.

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UDP (User Datagram Protocol)

UDP is a connectionless communication protocol used for sending data quickly without ensuring reliability or order.

Key Features

• UDP Does not establish a connection before sending data.

• Faster than TCP because it does not check error and it is connectionless.

• Mostly use in video calling, online games etc.

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DNS (Domain Name System)

Imagine you want to call your friend. You know their name, but not their phone number. You look up their name in your phone's contact list. The contact list tells you their phone number. DNS does the same thing for websites.

How it works

• You type a website address (like www.kads.in) into your web browser.

• Your computer doesn't understand that name.

• It asks a DNS server for the website's actual address (called an IP address).

• The DNS server looks up the website's name in its database and gives your computer the corresponding IP address.

• Your computer then uses that IP address to connect to the website.

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