How does a search engine find the answer?
📖 In short
You type your question into a search engine, and in less than a second pages from all over the world appear. How did it find them so fast among billions of pages? The secret is that it read and sorted them long before you asked!
🤩 Did you know?
- People make billions of searches every day.
- Before search engines there were lists of websites that people wrote by hand, like a phone book.
- Some search engines can search with a picture instead of words.
- Some websites remember what you searched for to show you ads, so it's wise to search carefully.
🔎 Find out more
🌟 The spiders that read the internet
A search engine sends out little programs called “spiders” that roam the internet day and night. They read every page, then follow its links to other pages, and so visit billions of pages.
🔍 A giant index
The search engine writes down every word and where it found it, like the index at the back of a book. So when you search for “giraffe”, it doesn't read the whole internet again; it goes straight to the word “giraffe” in its index.
💡 Who comes first?
Search engines use algorithms to rank the results: a page that clearly talks about your topic, and that lots of trusted websites link to, usually appears near the top.
🎯 Search smart
Type a few clear words, like “giraffe food”, instead of a long sentence. And remember the first result isn't always right: compare more than one source, and ask a grown-up if you're unsure.
🧭 How to write your question
Write only the important words: “biggest animal in the world” is better than a long sentence with “please” and “I want to know”. And if you don't find what you want, try other words with the same meaning.
🌈 Safe search
Many search engines have a “safe search” option that hides pictures and pages unsuitable for children. Ask your parents to switch it on.
📊 See how it works
📚 Key words
- Search engine
- A website that finds pages from your words
- Keywords
- The important words you type into a search
- Index
- The list of words and where they are in the pages
🧪 Try it at home
A search contest with your family: pick a question like “How many years does a tortoise live?” and look it up in a book, then online. Are the two answers similar? Which source do you trust more, and why?
🧩 Test yourself
1 What are the programs that roam the internet reading pages called?
2 Is the first result always right?