What is a set?

Answer:
A set, as it pertains to training, is a way

to measure a certain amount of a particular exercise. For instance, if someone does a set of bench press, he or she would lie down on the bench, take the barbell, and perform the exercise for a number of repetitions.

The number of repetitions can be anywhere from one to whatever. Once the trainee is finished with the number of repetitions, he or she has finished a set. Often, you will see workout routines written out as 3 sets of 10, or 2 sets of 8-12, and so on. Many of these types of workouts are just arbitrary. This is why I prefer my sets to be one set to failure.