The server: a computer that serves everyone
📖 In short
When you open a website, watch a video or send a message, your device asks for what it wants from another faraway computer called a “server”. The server stays awake day and night, waiting for requests from thousands of people at once, and sends each one what they asked for, like a busy waiter in a very big restaurant.
🤩 Did you know?
- A server usually needs no screen or keyboard, because people control it from far away.
- The number 404 has become so famous that some websites draw funny pages to say the page doesn't exist.
- A single data center can hold tens of thousands of servers.
- When you play a game online with friends, the server works out where each player is and tells the others dozens of times a second.
🔎 Find out more
🌟 Client and server
Your device, which asks, is called the “client”, and the computer that answers is called the “server”. The client says: “Give me the animals page”, and the server finds it and sends it. If it can't find it, it answers: “404: page not found”.
🔍 Servers for everything
There are servers for websites, mail servers that keep messages until their owners read them, game servers that bring players together in one world, and video servers that store millions of clips.
💡 In huge buildings
Servers sit on long racks inside “data centers”. They hold thousands of computers, powerful air conditioning to cool them, and backup power so they never stop if the electricity goes off.
🎯 When the server gets busy
If millions of people ask for the same thing at the same moment, the server may slow down or stop. So big websites share their work among many servers in different countries, and your request goes to the one nearest you.
🧭 Servers and speed
The closer the server is to you, the faster the page arrives. That's why big websites keep copies of their pages on servers on many continents.
🌈 Is my computer a server?
Any computer can become a server if we run a program on it that answers requests. But real servers are built to work for years without stopping.
📊 See how it works
📚 Key words
- client
- The device that asks
- server
- The computer that answers
- 404
- The server's reply when it can't find the page
🧪 Try it at home
The restaurant game: you're the waiter (the server), and your family are customers (clients) ordering from a little “menu”. Serve the orders in turn, and if someone asks for something that isn't there, say: “404, not found!”
🧩 Test yourself
1 What do we call the device that asks for the page?
2 What does the server answer if it can't find the page?