doteveryone explains

Uploading a photo: where is data sent?

The upload data is sent to a particular URL, which is like a postal address.

A URL describes a location on the internet. That could be a page on a website (like the BBC Weather Watchers home page) or a place to send data to.

The domain is a friendly name for the computer we're sending it to. The path describes where on that computer to send it.

In the URL '', '' is the domain, and '/weatherwatchers/upload' is the path

Your device needs to turn the domain into an IP address (internet protocol). This is a unique string of numbers, and every device on the internet has one. You can find yours out easily by typing 'What's my IP address' into Google, or clicking here to search.

Your device finds out the BBC's IP address by sending a request to the domain name system (DNS) which records all IP addresses.

Now find out how your data is sent and always arrives complete.