Take the time to read the search tips on the respective sites. Most engines, but not all, return results that include any of the words. Because there is so much information online, you will usually want to limit the scope of your searches. This is a good point to digress a bit to talk about Boolean operators. The English mathematician, George Boole, developed an algebra of logic, which has become the basis for computer database searches.
Boolean logic uses words called operators to determine whether a statement is true or false.
The most common operators are AND , OR and NOT . These three little words can be enormously helpful when doing online searches. A few examples show why. The exact syntax each engine uses varies, so familiarize yourself with each one's unique properties. Metasearches Rather than search each directory or index individually, you can submit your query simultaneously to multiple search engines by doing a metasearch .