Online directories and search engines provide links to websites and help users search the Internet for information. Most on line directories provide basic information about companies in specific industries or market segments. For example, an online directory for manufacturers may list each supplier’s name, address, phone number and basic product offerings. Search engines can provide this same information, along with targeted web results based on keywords and other advanced criteria. Examples of online directories and search engines include popular web sites such as Google, MSN and Yahoo as well as domain-specific search solutions such as Engineering360.

Selecting Online Directories and Search Engines

Selecting online directories and search engines requires an understanding of the differences between the two. In their simplest form, online directories list companies that provide specific products and services. An online directory may also enable users to search other websites, typically by choosing links to sponsored web sites and portals. Portals often provide services and resources such as e-mail, instant messaging, audio and video feeds, and links to popular web sites. By contrast, a web search engine allows users to search for news, images, and web links by typing a keyword or a keyword phrase. Specialized online directories and search engines such as Engineering360 allow users to find products based on performance specifications or a company’s geographic location.

Online directories and search engines are written in programming languages such as C++ and require a large number of servers to store data. Search engines such as Google, MSN, and Yahoo crawl hundreds of millions of web pages each day and index them for retrieval. To enable users to perform millions of searches, the largest search engines use a series of algorithms. Domain-specific search engines also use algorithms to provide targeted results. By using clustering techniques, these online directories and search engines can also find web pages with related terms.