A search engine is a set of programs used to search for information in a specific domain and group that information into a database. People often use this term in reference to Internet search engines, which are designed specifically to search the Internet, but can also be designed for offline content, such as a library catalog, the contents of a personal hard drive or a catalog of museum collections. . These programs help people organize and display information in a way that makes it easily accessible.
Internet search engines help users find information relevant to what they are looking for.
There are three aspects to a search engine: crawling, indexing, and searching. When you crawl, you’re looking for new content that wasn’t present during the last crawl, including updates to files and web pages. The programs then index the information and extract specific keywords to categorize it. On the Internet, for example, indexing relies heavily on web page keywords and meta tags that provide information about the page.
A library catalog is an example of an offline search engine.
Once the information is indexed, the information on how to access it is stored in a database. Some programs also store or “cache” information for easy retrieval. When someone searches the database, it displays the results sorted by relevance. On wiseGEEK, for example, a search for “giraffe” will return articles related to giraffes, including, of course, “What is a giraffe?”
Although all search engines work in a similar way, their usefulness can be quite varied. They rely heavily on complex algorithms to rank the relevance of their search results, especially those for common keywords. Users tend to gravitate towards those who return results they like, with Internet sites like Google®, Yahoo! ® and Bing® fight for users with multiple features designed to make their searches more engaging and relevant.
Google® has managed to become so associated with the process of conducting a web search that this process is often referred to as “Google searching.” The company is not too happy about this, as it fears that the lowercase use of its name, along with generic use, could contribute to brand dilution.
Many Internet search engines are smart enough to learn from their users by incorporating user activities into their relevance rankings. They also rely on information like links from other pages and a site’s reputation to rank in search results, all within the fraction of a section. Expert users can sometimes manipulate search results, but many programs change and evolve to help combat this practice.
Search engines allow people to find relevant search results.
