The Internet

A global network of physical cables and routers that allows computers to communicate.

Internet3 min readConcept 1 of 35

What is the Internet?

The Internet is a massive, global network of computers connected to each other. It is fundamentally a 'network of networks'.

It consists of both **hardware** (physical cables like undersea fiber optics, routers, and switches) and **software** (protocols that dictate how data navigates that hardware).

Why it matters

Web developers build applications that sit on top of this physical infrastructure. Understanding it helps you reason about performance and security.

Because data is bound by the speed of light and physical distance, every 'hop' between routers adds latency. Because data travels through dozens of third-party physical routers, encryption (HTTPS) is absolutely necessary.

How it works

When a device sends data over the internet, it isn't sent as one giant file. Instead, the TCP/IP protocol breaks it down into small chunks called **packets**.

These packets travel across various routers and cables to reach their destination IP address. Because the network is decentralized, packets from the same file might take entirely different physical routes to avoid traffic congestion or broken links.

Packet Routing Simulator

Send a message through the network. Watch how the data breaks into packets and dynamically routes across nodes to reach its destination.

// The Internet is a decentralized network // of physical routers. const sendFile = (data) => { // 1. Break data into small packets const packets = breakIntoPackets(data); // 2. Route independently (TCP/IP) packets.forEach(packet => { routeToDestination(packet, serverIP); }); // Note: If a physical router fails, // packets dynamically find another path! };
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Check yourself

Pick an answer to lock it in, then read why. Getting one wrong is part of how it sticks.

  1. 1What is the fundamental difference between the Internet and the World Wide Web?
  2. 2In the context of the Internet, what is the primary role of 'packets'?
  3. 3How do devices on the Internet know exactly where to send data to each other?

Remember this

  • The Internet is physical hardware and network rules. The Web is just one application built on top of it.
  • Data is chopped into packets which find their own path through routers across the world.
  • Everything operates on unique IP Addresses.

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