Search engines are programs that search the Internet on a regular basis for new sites to add. In fact, most of the websites that show up in search results aren’t manually added, but are found and added by web crawlers as they search the web.
Search engines work in three stages:
1) Crawling: Search engines use automated programs called “crawlers” to search the web for pages that have been changed or added. They put them on a big list for later. They find pages on the web by many different methods, but the main method is by following links from pages that they already know about.
2) Indexing: When a search engine crawls, it visits the pages it has learned about and tries to figure out what each page is about. They look at the text, images, and videos on the page to figure out what the page is about. This information is stored in their index, which is a huge database that is stored on many computers around the world.
3) Serving search results: When someone searches on a search engine, they try to figure out which results are the best. The “best” results are based on a lot of things, like
- where the user is,
- what language they speak,
- what type of device they use (desktop or phone), and
- what they’ve already looked up.
You might get different results if you search “bicycle repair shops” in Paris and in Hong Kong.