Search Engines
A search engine is basically a coordinated set of computer programs that indexes web pages so that web surfers can locate these web pages by entering relevant search queries, usually in the form of keywords and keyword phrases. There are about 370 odd listed search engines available for web surfers to use, with about ten major ones (although some use other search engine's technology and vice versa).
Typically a search engine consists of four components, namely spider, index, relevancy algorithms and search results. Search engines work by sending out spiders (also known as a crawlers or a bots) to crawl as many web pages as possible. These pages are then read and indexed according to the words found in each page.
The relevance of a given page is rated by the relevancy algorithm, and matched to specific search queries by the search results component of the given search engine. Search engines are typically geared towards returning relevant, organic results and disregard banners and other rich media in their search.
PageRank gets assigned to indexed web pages and the highest rankings for a particular search query will be at the top of the page of the returned search results, ensuring that the web surfer gets the most relevant and authoritive information.
Now that we've discussed search engines we're going to take a look at Deep Links