Straight Sets - a number of repititions followed by a rest, then another set and repeat until all assigned sets of that exercise are complete. Then move to the next exercise.
Super Sets - a set of two different exercises done back to back without rest in between. Rest. Repeat. Click here for a more complete explanation.
Giant Sets - a set of 3 different exercises perfomed back to back without rest in between. Rest. Repeat.
Drop Sets - several sets of the same exercise performed back to back with very little rest in between. Often each successive set of exercise is done with a lighter weight or fewer reps.
Circuit Sets - moving from one exercise to another in rapid succession taking very little rest. Generally, a circuit has 7 exercises and is regulated by heart rate. Repeat for assigned rounds.
Burnout Sets (B/O) - A single set of exercise done to complete exhaustion. Note: "complete exhaustion" occurs upon breakdown of productive form for a given exercise.