Genealogy portals have just as much variety and include many of the categories covered in this lecture. They can be overwhelming in their offerings. Many different robotic programs are indexing the Internet around the clock. Search Engines are computer programs that search one or more of these indexes. This is why each search engine searches differently and comes up with different results.
Many Web sites have site-specific search engines which index just their Web site.
On the other hand, meta search engines simultaneously search multiple search engines. They are often in the retail business of selling books, software, and other genealogical materials. One of the best things they do for genealogists is to make available databases which otherwise would not be readily affordable or accessible to the general public. These companies invest in the expense of making these databases searchable online, then charge subscribers minimal fees to access the information. Often you can search their collection of databases for free, but you must pay to obtain detailed information from the results of your search.