Strength exercises include “reps and sets”. The “reps” is short for repetition and that is the number of consecutive times you are going to reproduce the movement (10 bicep curls). The “set” is how many times you are going to reproduces the repetitions of that exercise ( 3 sets of 10 reps). So in the example stated, you would have performed 30 bicep curls. People who are trying to maintain “tone” would benefit from strength exercises that consist of moderate resistance and perform a higher amount of repetitions.