Internet Basics- Crash Course

Whether you’re building APIs or just consuming them, understanding how the Internet works is like knowing the roads before you start driving. In this post we will go through a brief overview of Computer Networks.

What Is the Internet?

Internet is a giant network of networks. Billions of devices - laptops, phones, servers all connected together, talking via shared rules.

What About the Web?

The World Wide Web (WWW) is a service that uses the Internet. It’s the collection of websites, documents and multimedia content that your browser fetches (chrome, firefox etc) when you go to say, https://csprimer.in.

What Are Web Protocols?

Web protocols are rules that help different parts of the Internet talk to each other. When you use a web browser, it shows you information from a server in form of a web page. This information travels between your browser and the server using a protocol called HTTP.

Other examples of protocols are - FTP, SMTP that send information over the internet and use lower level protocol TCP, UDP, IP.

HTTP - The Language of the Web

When you type a URL into your browser or call an API, you’re using HTTP (Hypertext Transfer Protocol) - a request/response based protocol.

Example:

GET /hello HTTP/1.1
Host: csprimer.in

GET is the HTTP method (retrieve data), /hello is the API endpoint. Headers often include things like Authorization: Bearer ( Used in JWT Auth ) and Content-Type: application/json (which kind of data is being sent)

The server replies with something like:

200 OK
Content-Type: text/html

<html><body>Hello world!</body></html>

Where Does TCP/IP Fit In?

HTTP relies on lower-level protocols for correct communication between you and websites.

TCP (Transmission Control Protocol) - Think of this like sending a set of numbered envelopes, it guarantees that all your data arrives and in the correct order.
IP (Internet Protocol) - This handles where the data goes (its like the mailing address).

Conclusion