A search engine enables you to find specific information within the huge mass of data that's stored on the internet. It's usually a dedicated website, but it can take the form of an 'app' on a hand-held device or simply be a 'search window' on a website that can be about almost anything.
By typing words into the box on the home page of a search engine such as Google and clicking Search, a page will be displayed containing results – that is, links to web pages – related to the search terms (also known as 'key words') you've entered. These results, commonly known as ‘hits’, will usually be listed in order of relevance to the exact terms entered. Some search engines even display results that are tailored to your previous search activity.