Search engines are electronic tools used to search the internet. There are a many search engines besides Google, Yahoo and Bing. The ones that we are most familiar with are general search engines.
There are also some search engines that will search other search engines to add to their results. They are called Meta Search Engines.
Then there are those types of search engines that really do not fit into a specific category or focus on a specific type of information.
As you can see from the lists below, there is a wide variety of ways to search the internet.
General Search Engines
Meta Search Engines
Other Search Engines
Searches for forums and message boards on a specific topic of interest
Looks for copyright free material such as music, books, and videos
Looks at the massive material published on the World Wide Web on almost any topic. It includes free videos, books, music and software
Looks for documented slide shows, ebooks, and PDFs
Looks for wiki's on almost any topic.