definition of a search engine.
Let's take a moment to stand back. You need to understand search
engines before you can get into SEO specifics. A search engine is a
piece of computer software that is used to look for specific
information on the World Wide Web by searching data (like text or a
database). What you see after searching is referred to as a SERP, or
Search Engine Results Page. Here is a link to our complete
vocabulary.