Motores de busqueda

SEARCH ENGINES 

Search Results

A web search engine is a software system that is designed to search for information on the World Wide Web. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs). The information may be a mix of web pages, images and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler. Internet content that is not capable of being searched by a web search engine is generally described as the deep web.

Advanced Search

Web search engines get their information by web craling from site to site. The "spider" checks for the standard filename robots.txt, addressed to it, before sending certain information back to be INDEXED depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, as evidenced by the standard HTMLmarkup of the informational content, or its metadata in HTML meta tags. "[N]o web crawler may actually crawl the entire reachable web. Due to infinite websites, spider traps, spam, and other exigencies of the real web, crawlers instead apply a crawl policy to determine when the crawling of a site should be deemed sufficient. Some sites are crawled exhaustively, while others are crawled only partially".