"Boolean operators" are the connector words that are used to combine sets of search results to achieve certain desired effects. They are named for George Boole, a 19th century English mathematician. The most commonly used Boolean operators are AND, OR, and NOT.
Here is a handy "rule of thumb" for the Boolean operators AND and OR:
For more information about Boolean operators, check out these resources:
Well, this can be a problem indeed! Here are some tactics to try:
This can be as much of a problem as getting too few results. Try one of these strategies to simultaneously reduce the numbers of hits, and focus the results: