4. Search Engine
A search engine indexes the web pages on the World Wide Web. It uses different methods to index them such as the URL (the unique web page address), the page title and keywords that appear in the text.
To find relevant web sites you type in your keywords into the search box. The search engine then searches through the billions of web pages stored in its database index to find the best matches.
Because the search engine will probably find thousands of results it needs a way of showing you the most relevant pages first. To do this it uses a complicated algorithm which factors in a number of different things such as the number of external links to the webpage.
You will then be presented with a list of results with the most appropriate ones on the first page. There will be a title for each result, a short text introduction so that you can judge what the web page contains and then the url link to the web page. All of this happens in a fraction of a second.
There are many search engines on the Web. You probably stick to the same one out of habit. But it is worth exploring the others as well as they all return a different list of web pages.
No single search engine has indexed the whole of the web.
Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: list of search engines