How the internet actually works

Tech Guides

How the internet actually works: a clear explanation from start to finish

Informatics HubJuly 20267 min read

Most people use the internet every day without having any real idea how it works. That is completely fine for a regular user. But for anyone building software, working with APIs, or designing systems, understanding what happens between typing a URL and seeing a web page is foundational knowledge that changes how you think about everything.

This is not going to be a textbook explanation full of OSI layers and protocol numbers. It is going to be a clear, honest walkthrough of what actually happens when you open your browser and visit a website.

What the internet physically is

The internet is a global network of computers connected to each other through cables, fiber optic lines, wireless signals, and satellites. At the most basic level it is just machines talking to other machines through wires and radio waves. The magic is in the protocols, which are the agreed-upon rules that allow all those different machines made by different companies in different countries to understand each other.

The internet is not a cloud. It is not invisible. It is millions of physical cables running under oceans, through mountains, and along roads connecting buildings full of servers that are on twenty four hours a day.

Every website you visit is stored on a physical server somewhere in the world

What happens when you type a URL

The full request journey

1

DNS lookup — your browser needs to find the IP address of the server behind the domain name you typed. It contacts a DNS server which works like the internet's phone book, translating informaticshub.com into something like 104.21.58.130

2

TCP connection — your computer establishes a reliable connection to that IP address using a protocol called TCP. This involves a handshake where both sides confirm they are ready to communicate

3

HTTPS and TLS — if the site uses HTTPS (which all modern sites should), an encrypted tunnel is established using TLS so that nobody can read the data passing between you and the server

4

HTTP request — your browser sends an HTTP GET request to the server asking for the web page at that specific URL

5

Server response — the server processes the request and sends back an HTTP response containing the HTML, CSS, and JavaScript that make up the page

6

Browser rendering — your browser reads the HTML, loads the CSS to style it, runs the JavaScript, and renders the final visual page you see on screen

IP addresses and what they mean

Every device connected to the internet has an IP address. It is a unique numerical identifier that tells the network where to send data. When you request a web page, the server needs to know where to send the response. Your IP address is that return address.

IPv4 addresses look like four numbers separated by dots: 192.168.1.1. Because the internet ran out of unique IPv4 addresses, a newer system called IPv6 was created with a much larger address space. Your router typically handles the translation between your local network and the public internet through a process called NAT.

Why HTTPS matters

HTTP sends data as plain text. Anyone between you and the server who can intercept the connection can read everything. HTTPS encrypts the data so that even if someone intercepts it, they cannot read it. This is why your browser shows a padlock icon for HTTPS sites and warns you about HTTP ones. It is not optional for any serious website in 2026.

Why this matters for developers

Understanding the request and response cycle is the foundation of all web and API development. When an API call fails, you debug it by looking at the HTTP status code, the request headers, and the response body. When a site loads slowly, you look at DNS resolution time, connection time, and time to first byte. None of this makes sense without understanding what is happening at each step.

Key takeaways

• The internet is physical infrastructure connecting machines through cables and wireless signals
• DNS translates domain names into IP addresses so browsers can find the right server
• Every web request goes through DNS lookup, TCP connection, TLS handshake, HTTP request, and server response
• HTTPS encrypts the connection so intercepted data cannot be read