The AND operator is a short way of saying that all of the search terms have to be in the records returned. This AND differs from the English "and". In English we might say "I want books on Cats and Dogs" - meaning that any book on cats would be acceptable, any book on dogs would be acceptable, and any book on both cats and dogs would be acceptable. This connotation is the equivalent of the OR operator in Boolean logic. The AND operator would find only books on both cats AND dogs acceptable. To illustrate this concept, we will use the following diagrams. Imagine that all the records that contain the word cats exist in the circle labeled Cats below and all the records that contain the word dogs exist in the circle labeled Dogs. Those records that had both words, cats AND dogs, exist in the shaded area and are returned when that search (cats AND dogs) is performed. Note that the AND search returns a small number of records. |