Take the time read the search tips on the respective sites. Most, but not all, engines 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 logic. 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 will show you why. The exact syntax each engine uses varies, so familiarize yourself with its unique properties. One last word of advice.