How the Internet works

You type a web address, press enter and a page appears in about a second. Behind that second is a chain of steps that spans the globe. Here's how the internet works in plain English: where it came from, how a website gets from a domain name to your screen, how AI may change it, and why the "dark web" isn't quite what its name suggests.

• 1969 the first message

  Two computers in California swapped the first message on ARPANET, the internet's forerunner.

• 6bn people online

  About three-quarters of the world's population in 2025, according to the ITU.

• 57% of web requests

  The approximate share made by bots on Cloudflare's network in June 2026, as reported from Cloudflare Radar.

What is the internet?

The internet is a worldwide network of networks. Millions of separate networks, run by phone companies, businesses, universities and governments, have agreed to pass data to one another using the same rules. Nobody owns all of it, and there's no central off switch.

The internet and the web aren't the same thing. The internet is the roads: the cables, routers and rules that move data. The World Wide Web is one of the things that travels on those roads, along with email, video calls and online games.

A short history of the internet

On 29 October 1969, a student at UCLA tried to log in to a computer at the Stanford Research Institute over ARPANET, a network funded by the US Department of Defense. He meant to type "login", but the system crashed after two letters. So the first message ever sent was "LO".

ARPANET worked, but networks of different types couldn't talk to each other. In May 1974, Vint Cerf and Bob Kahn published a paper describing a way to link them, which became TCP/IP, the rules the internet still runs on. ARPANET switched over to it on 1 January 1983, a date often called the internet's birthday. That work is why Cerf and Kahn are known as the fathers of the internet.

Two more inventions made it easy to use. In 1983, Paul Mockapetris invented the Domain Name System, so people could use names rather than numbers. In March 1989, Tim Berners-Lee, a British scientist at CERN, proposed what became the World Wide Web, and the first web server and browser were running by the end of 1990.

How data travels: packets and IP addresses

Every device on the internet has an IP address, a number such as 203.0.113.10 that works like a postal address. Data doesn't travel in one piece. It's cut into small packets, each labelled with where it's going and where it came from.

Think of sending a book by post, one page per envelope. The envelopes can take different routes, and the person at the other end puts the pages back in order. IP gets each envelope to the right address. TCP checks that they all arrived and asks for any missing ones again. Routers along the way pass each packet towards its destination, over fibre-optic cable, including cables on the sea bed, and finally over your broadband, mobile signal or Wi-Fi.

From domain name to live website: how it's set up

These are the steps we follow to put a business website online.

1. Register a domain name

   You choose a name, such as cirrusdesignstudio.co.uk, and register it through a company called a registrar. You don't buy it outright: you rent it and renew it, usually each year or every few years. Make sure it's registered in your business's name. Nominet looks after the .uk part of the internet.

2. Choose your web hosting

   Hosting is the computer, called a server, that stores your website and is switched on all day, every day. Think of the domain as your address and the hosting as the building. Where it's located matters too, which we cover in where your business data actually lives.

3. Connect the two with DNS

   DNS records tell the world where to find your services. An A record points your domain to your server's IP address, and an MX record says where your email should go. Changes can take a little while to spread around the world.

4. Add an SSL certificate

   This is what gives you https://. It encrypts the connection between the visitor and your site, and shows browsers that they're talking to the right website.

5. Build and publish the website

   The design, content and code go on the server. Many sites use a content management system, such as our own Hydra CMS, so your team can update pages without touching code. Our website design service covers these steps, and our website questions page answers the common ones.

6. Keep it looked after

   Launch day isn't the end. Software needs updating, backups need testing and renewals need paying. Our website maintenance checklist covers what to check, and our piece on the PHP2Shell security flaws shows why it matters. It's also worth protecting your domain and hosting logins with a strong password and two-step verification.

What happens when you visit a website?

Once a site is live, this all happens in a moment each time someone visits:

1. You enter the address

   Your browser first checks whether it already knows the site's IP address from a recent visit.

2. DNS finds the number

   If not, a DNS resolver, usually run by your broadband provider, finds out. It asks a root server, which points it to the servers for .uk, which point it to the servers holding that domain's records. DNS is often called the address book of the internet.

3. Your browser connects securely

   It contacts the server at that address and the two set up an encrypted HTTPS connection.

4. The server sends the page

   Your browser asks for the page, and the server sends it back as packets.

5. Your browser builds it

   It reassembles the packets, requests the images, styles and scripts the page needs, and draws the result on your screen.

How AI may revolutionise the internet

The internet's basic plumbing isn't about to be replaced, but how we use it may change a great deal. Nobody knows exactly how this will play out, but here are four changes we're watching:

AI could also help run networks, spotting faults and attacks sooner, although attackers can use it too. For the latest developments, see our AI news round-up for October 2026.

The "dark net": mislabelled and misunderstood

"Dark net" sounds sinister, but the name says more about how it's found than what it's for. It helps to separate three terms:

• The surface web: public pages that search engines can find, like this one.
• The deep web: pages that search engines can't reach, such as your online banking, email inbox or a client portal. Most people use it every day.
• The dark web: sites on networks such as Tor, which you can't reach with a standard browser. The networks themselves are often called the dark net.

"Dark" here means hidden from view, not illegal. Criminal marketplaces do exist there, and they're the reason for its reputation, but the technology is a privacy tool. Using Tor isn't in itself illegal in the UK, while anything illegal offline stays illegal on it.

Tor has surprisingly official roots: the idea of onion routing began at the US Naval Research Lab in 1995, to hide who is talking to whom. Today it's used by journalists and their sources, activists, and people living under censorship. ProPublica launched an onion site in 2016, followed by The New York Times in 2017 and BBC News in 2019, the BBC's aim being to reach audiences in countries where its news is blocked or restricted.

How .onion works

A .onion address isn't part of normal DNS. No registrar sells it and no central directory hands it out. Instead, it's created from the site's own cryptographic key, which is why addresses are a 56-character jumble of letters and numbers. The address itself proves you've reached the right site. To open one, you use the Tor Browser.

The "onion" part comes from layers of encryption. Your traffic is wrapped in several layers and passed through a chain of volunteer-run computers called relays. Each relay peels off one layer, so it only knows the step before and the step after it. No single relay sees both who you are and where you're going.

A connection to an onion site goes further, so that neither side learns where the other is:

1. The site sets up contact points

   It chooses a few relays as "introduction points" and publishes the list, signed with its key.

2. You pick a meeting place

   Your browser finds that list, chooses another relay as a "rendezvous point" and gives it a one-time secret.

3. You send an introduction

   Through an introduction point, you tell the site where to meet and share the secret.

4. You meet in the middle

   The site connects to the rendezvous point and presents the secret. The full path is six relays, three chosen by each side, and it's encrypted from end to end.

Privacy has a cost: all those extra steps make Tor slower than the normal web. And it isn't magic, as it hides your location but won't protect you from a scam or from malware you choose to download.

How the internet works: quick answers

Need help getting your business online?

You don't need to know how the internet works to run a great website, because that's our job. Whether you need a new site, a domain moved or just a clear explanation of what you've got, we're happy to talk it through.

Talk to us See our website design service

This article is general information, not legal advice.