What happens when you type a web address and press Enter
IP addresses: why the internet cannot use a website's name
You type the name of a website. But the internet cannot use that name. The machines that carry your request read something else.
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Watch a message from someone else reach a machine on the way. The machine reads one line, a number, and sends the message one step closer to it.
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That number is how a computer is reached on the internet, and it is called an IP address. The server of the website is reached at one, like 198.51.100.7 here.
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Every message also carries the IP address it comes from, so an answer can find its way back: that number becomes the "to" line of the answer. Yours is given to you by the network you connect through.
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Names exist for people: a name is easy to remember, and a string of numbers is not. The machines never needed them.
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Your request has a name and an empty "to" line, and your phone does not have this number yet. Still, a moment after you press Enter, the right one is there, out of billions. Who told it?
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Quick check
A message says "to: shop.example.com", and its number line is empty. Can a machine on the way pass it on?
Show the answer
No. A machine on the way reads only the IP address on the "to" line, so a message with no number goes nowhere.
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Go further
Where the name comes from, and the two kinds of IP address in use today.