During the dips exercise (chest version) the main burden lies with the chest and upper arm three-headed muscle. A little stress on the anterior part of the deltoid muscle as well. Exercise can be performed by neutral grasp or prone (palms facing away from you) grip. In both cases, the initial position with the hands straight at full, while look directed towards the horizon.
You should slowly lower your torso until impact stretching the shoulder joints. Then, start moving back to starting position. During the dips exercise for the chest torso should lean about 30 -35 degrees or so, for the proper form. Otherwise the main burden during the exercise will be transferred to the triceps.
For the advanced trainees additional wights may be attached for the increased stress.