Search Engines. Search Engines are computer programs designed to search web pages by using keywords. To compile their databases, search engines rely on computer programs called "robots" or, more specifically, "spiders." These programs "crawl" across the web by following links from site to site and indexing each site they visit. Each search engine uses its own set of criteria to decide what to include in its database.
How does a search engine work? Words or phrases entered in the search box are matched to resources in the search engine's database that contain your terms. These are sorted and presented with the most "relevant” sites appearing first.
How search results are organized. A search engine has gathered its matches from its database, the engine lists or "ranks" the resulting sites in order of its own estimation of their relevance. Search engines predict relevance based on two sets of factors: those based on a site's content and those external to the site.
