HOW THE INTERNET WORKS
Before discussing how the internet works, let’s first talk about the definition of a network. What is meant by a network?

A network is a group of computers that are connected and can exchange data with each other. A computer network is like a social circle, where a group of people who know each other can exchange information and coordinate activities together.
The Internet is a vast and distributed collection of interconnected networks. In fact, the word "Internet" comes from this concept: interconnected networks.
Because computers are connected to one another in a network, and these networks are also connected to each other, one computer can communicate with another computer in a distant network thanks to the internet. This allows for fast information exchange between computers around the world.
Computers connect to the internet through cables, radio waves, and other types of network infrastructure. All the data sent through the internet is translated into pulses of light or electricity, also known as bits, and then interpreted by the receiving computer. Cables, wires, and radio waves carry these bits at the speed of light. The more bits that can travel through these cables and wires at once, the faster the internet works.

Decentralization: Why Doesn’t the Internet Have an “Off” Button?

One of the coolest things about the internet is that it doesn't have a central control. Its architecture is called distributed.
Here’s the difference between centralized and distributed internet architecture:

  • Centralized Network: Like a bicycle wheel. All the spokes are connected to a single central point. If the center breaks, the entire wheel collapses.
  • Distributed Network: The internet is more like a fishing net. If one part tears, the net as a whole still works and can be used. Data or information simply finds another intact path.

This distributed nature of the internet is what makes it incredibly resilient. Unlike a computer, which might stop working if one part is missing, the internet allows computers and servers to turn on or off at any time without breaking the entire system. Even if a major data center or an undersea cable fails, data traffic will automatically be rerouted through other paths. The connection may slow down a bit, but the internet will never completely “shut down.”
     

How Does It Work?

To make the internet function and connect billions of devices around the world, there are two main concepts at its core: data packets and communication protocols.
1. Packets

When we send data over the internet — like opening a web page, sending a message, or watching a video — the data isn’t sent all at once. Instead, it’s broken down into small parts called packets.
Each packet contains two parts: the data itself and extra information called a header. The header tells where the packet is going, where it came from, and how to reassemble it. It's like sending a build-it-yourself toy with assembly instructions so it can be put back together correctly.
When data is sent over the internet, it is first broken into small packets, then translated into bits. These packets are routed to their destination by various network devices like routers and switches. When the packets arrive at their destination, the receiving device reassembles them in order and can then use or display the data.
To send these packets, the internet uses a system called packet switching. This system allows each packet to take a different path to the destination, depending on which route is fastest or least congested. Once all packets arrive, they’re reassembled into complete data.
Without this system, every computer would have to maintain a direct and constant connection to another computer to exchange data. As a result, only a few users could access the internet at the same time. With packet switching, millions of people can exchange data at the same time efficiently.

  
2. Protocols

Because the internet connects different types of devices and operating systems from all over the world, it needs a universal rule so that they can "talk" to each other. This rule is called a protocol.
A protocol is a set of rules that govern how data is sent, received, and interpreted by devices.
Just like two people from different countries need to use a common language to understand each other, protocols allow devices in a network to communicate clearly.
There are many types of protocols, each with a specific function. Examples include:

  • Ethernet: used for communication between devices in a local network.
  • IP (Internet Protocol): responsible for sending data from one network to another.
  • TCP (Transmission Control Protocol): ensures data arrives complete and in the correct order.
  • HTTP (HyperText Transfer Protocol): used when accessing web pages.

In addition, there are other protocols for things like encryption (security), network testing, and media streaming — for example, UDP, which is faster than TCP but less reliable in making sure all packets are received.
Because all internet-connected devices use the same protocols, they can connect and exchange information, regardless of the brand or type of device.
 
     

Physical Infrastructure of the Internet

For all this to work, we need hardware and physical infrastructure to connect everything. Some key components include:

  • Router: This device directs internet traffic. It reads the packet's information and decides where it should go — like a traffic police officer directing vehicles.
  • Switch: Used to connect multiple devices in one network. It forwards packets to the correct devices within a local network and can also send data outside the network if needed.
  • Web Server: A special computer that stores data and content like web pages, images, or videos. When we access the internet, our requests are sent to the server, and the server sends back a response in the form of data. Servers also handle important services like DNS (website addresses), online apps, and databases.

These servers are usually located in data centers spread across the globe. They store and deliver large-scale data so that internet users can access information anytime and anywhere.
     

How Do Websites Appear on Your Screen?
When you open a website or app, you're actually requesting data from another computer called a server. That data is sent to your device in small packets, then reassembled by your browser (like Chrome or Safari) into the web page you see.
Here’s how it works in simple steps:
  1. DNS Request
    Your browser looks up the IP address of the website you're visiting (for example, turning www.cloudflare.com into an address like 104.16.132.229). It’s like finding someone’s phone number in a directory.
  2. TCP Handshake
    The browser opens a connection with the server using that IP address. This connection ensures both devices can send and receive data.
  1. TLS Handshake
    The browser and server agree on an encryption system so that data sent between them stays secure and can't be read by hackers on public Wi-Fi.
  2. HTTP Request
    Your browser asks for the contents of the web page — including text, images, layout, and more.
  3. HTTP Response
    The server sends all the requested data (usually in the form of HTML, CSS, and JavaScript) in thousands of small packets.
    Your device receives and checks all the packets, and then the browser reassembles them and displays the full web page you can read or interact with.