Spotter
A spotter is a person who ensures safety during weight training, by helping with picking up weights and ensuring help is at hand should the trainee reach muscular failure and cannot complete a repetition. Upon failure, the spotter prevents injury by helping the trainee return their weights to a safe position.
A good spotter is both a safety measure and a motivational tool. By training with a spotter you are free to increase your weights safely, which is of benefit to both your fitness and physique.