It's a huge repository of web pages and their addresses. By consulting a search engine we can find websites that contain the type of information we want. We can then visit those websites to find answers.
Search engines are actually huge databases of websites.
Before a website is listed, the search engine examines the website and tries to pick out the important keywords. The search engine then indexes the website. When you, as an Internet user, visit a search engine, you are able to type a few keywords into the search field. There are hundreds of search engines to choose from and knowing which one to use can be tough. Because Internet programmers figure if they can build a better search engine people will use it.