In some cases, the same results can be achieved when segmenting either by field or by query. For example, assume that the AcctType field in your database divides your customer accounts into Standard, Preferred and Premier levels. Segmenting by the AcctType field will create three segments for these account types. You could achieve the same results using queries, but creating the segments would require writing three separate queries. Determine the most efficient method based upon the data you are segmenting.