Within seconds a search engine can find 10,000 web sites containing your subject, rank them by the amount of your subject content, and list other features. Although the standard search mechanism for most of the search engines will serve most of your research needs, different features are available. Lycos for example, was one of the first to offer the choice of looking just in personal home pages as compared to all web sites.
Search engines change quickly.
They're adding new features constantly. It's best to check more than one while doing your research. In the summer of 1997, HotBot was considered the best search engine, but you decide what works best for you.