Websites are made up of words and images, all bundled up in files. The computer that stores these files could be anywhere in the world, but your computer can talk to it using the internet.
When you type in a web address like wikipedia.org, your computer is sent all the files by cables or wirelessly and shows them in a way that is easy to view.
Our story starts where every good story starts, with homework…
Imagine you have to write a story about the Romans – by tomorrow morning. And you don’t know anything about the Romans.
Let’s go to Wikipedia. That’s always a good place to start.
You open up the browser – like Google Chrome or Safari – on your iPad. The browser’s job is to read and show website files.
Most websites are written in a language called HTML, which stands for Hypertext Markup Language. The browser reads HTML and turns it into the words and images you see.
Using HTML, people give meaning to words by tagging them so a computer can read them. For example, you can create a page heading by putting <h1> at the start of your title, and </h1> at the end, like this: <h1>The Romans</h1>.
You start to type ‘Wikipedia’ into the box at the top of your browser. Look at that, your super-smart browser suggests Wikipedia.
There is a computer somewhere in the world that holds the files for Wikipedia. As soon as you press enter, your iPad will send a message to that computer asking for all the files it needs to show Wikipedia’s homepage.
You hit enter. Computers can talk because they’re connected to the internet – a network of computers, phones, and cables that covers the whole world.
Your iPad knows where the other computer is because everything connected to the internet has its own address – called an IP address. IP addresses give each computer a unique identity.
When the Wikipedia computer receives the request for files, it grabs them and sends them back.
This type of computer is called a server. A server is specially designed to hold files. And they are always on so they can send and receive files at any time of the day or night.
Your browser then takes those files and works out how to build and display them.
And Wikipedia is there. On your iPad.
This whole process takes just seconds in real life. Information travels around the internet at the speed of light. So it can travel around the world in the time it takes you to blink.