What is the internet?

In depth guide to how the internet works

The internet. It's a world at our fingertips, a constant hum of information and connection. But how exactly does it all work?

Networks

When computers are physically connected to each other, they form a Local Area Network, or LAN. If computer A wants to talk to computer B, it sends a signal directly to B. This allows them to share information and resources.

If B is on a different network entirely, computer A needs a different approach.

Private vs. Public IP Addresses

Private IP addresses are unique identifiers assigned to devices within a network. They are not routable on the public internet, meaning they can't be directly accessed from outside the network.

192.168.1.1

Public IP addresses are unique identifiers assigned to your entire network by your internet service provider (ISP). This address acts like your network's identification on the public internet, allowing other devices to find and connect to your network.

82.129.80.111

Packet Power: Breaking Big Data into Bite-Sized Pieces

Large files like videos or documents would take forever to send as a whole. To make things faster, they're chopped up into smaller packets. These packets contain the data itself and an addressing label, similar to a note on an envelope specifying the destination.

Routers: The Traffic Cops of the Internet

Routers are the unsung heroes of the internet. They act like traffic police, reading the address labels on data packets and directing them on the most efficient route towards their destination. Multiple routers work together, passing the packets along until they reach the right device.

How it works?

When a device on your network (like your computer) wants to access the internet, it sends a request to the router. This request includes the data you want to send and the destination address (e.g., a website) PACKET.

The router intercepts the request. It recognizes the device's private IP address and translates it to the public IP address assigned to your entire network. This allows the request to be recognized and routed on the public internet.(All done by NAT)

Putting it Back Together: Reassembly and The World Wide Web

Once the packets arrive at their destination, a switch or the device itself reassembles them in the correct order, just like putting together a puzzle. This reformed data is what allows you to see a website, play a song, or download a file.

The Final Piece: Your Internet Service Provider (ISP)

Think of your ISP as the on-ramp to the internet highway. They provide the connection between your home network and the larger internet infrastructure.

The Web vs. The Internet: A Subtle Difference

It is important to distinguish between the internet and the web. The internet is the vast network that allows communication, while the web is a service built on top of it. The web uses the internet's infrastructure to allow us to access websites and navigate information using web browsers.

This guide showed a simple example of how computers communicate with one another over the internet.