Search using Subject Directories - Subject directories select and classify resources into subject categories and subcategories. It is possible to search these categories by using keywords or by browsing through them. Subject Directories are somewhat limited in their breadth, but are good places to start looking for companies, organizations, and general subjects. LookSmart My Virtual Reference Desk Search using Search Engines - Search engines attempt to index as many sites as possible. Search features vary greatly, as does the actual scope, currency, and accuracy of the databases.
Meta engines are very helpful when an exhaustive web search is necessary.