Search engine software is used to index information on a website or intranet. Algorithms help users search a large corpus of data by keyword or a set of terms. The results are then presented in a prioritized list.
Typically, search engine software includes a Web crawler or spider, an indexer, a query engine, and a user interface. The Web crawler follows the hypertext markup language (HTML) links in Web pages to find documents. The indexer applies a rule set to these pages, indexes the content, and then saves the results for user searches. The query engine performs the actual search and returns ranked results that reflect search algorithms. Finally, the application interface enables users to interact with the query engine.
Differences in Search Engine Software
Search engine software differs in terms programming language, platform compatibility, and type. Typically, products are written in languages such as C, C++, Perl, Vortex-Tex, or Glimpse. Search engine software is also designed for use with specific operating systems (OS) or platforms. These include Microsoft Windows (Microsoft Corporation), UNIX (The Open Group), Linux (Linus Torvalds), and MacOS (Apple Computer). In terms of type, search engine software is available for web search engines, selection-based search engines, metasearch engines, desktop search tools, and specialized applications for web portals and vertical market websites.
Selecting Search Engine Software
Selecting search engine software requires an understanding of various product types or categories. Web search engines are designed to search for information such as web pages, images, and other files via the Internet. They operate algorithmically, or represent a combination of algorithmic and human input. By contrast, Web directories are human-edited. Search engine software for metasearch engines is also available. These search tools send users to other search engines or databases, and then aggregate the results in a single list or display. Selection-based search engines require only the use of mouse. Desktop search tools are designed to search only the contents of a computer, rather than across an intranet or website.
Typically, search engine software is used for applications such as indexing, metadata search, and semantic search. Indexing extracts interesting content from files and then catalogs that information for search and retrieval. Metadata searching allows users to find metadata, a term which is often defined as "information about information". Search engine software for semantic search uses data from semantic networks to clarify user queries in order to generate more relevant web results.