Standard beach shorts are the most common, and you'll find that most brands will have an extensive collection of this type. These are designed with the sole purpose of giving you flexibility and coverage without being overly flexible.
Standard swim trunks are quite loose around the legs but still offer optimal security around the waist. On average, the inseam will range between 4 and 6 inches, allowing the shorts to fall in the middle or below the knee.
You'll likely find standard beach shorts worn by surfers and others who love in-beach activities. You might also find that you can wear them for running errands or more casual outings.