A web search engine is software code 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 (SERP's). The information may be a specialist in web pages, images, information and other types of files. Some search engines also data mining|mine data available in databases or web directory|open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time computing|real-time information by running an algorithm on a web crawler.