Body-Weight Squats
The basic squat is an exercise which most people are familiar with. Keep your back straight and lower yourself until your knees are bending at a 90 degree angle. Breathe in on the way down, breathe out on the way up. But like many exercises that have been around so long and are so common place many variations of the basic squat have come into being.
Jump squat: The jump squat is a plyometric exercise variation on the traditional squat exercise where after coming to the down position of the squat one jumps up. I think that's why they call it the jump squat at-least. The benefit of this variation of the squat is to develop the explosive fast twitch fibers involved in jumping.
Box squat: The box squat variation uses a box or seat just behind the squatter. When coming to the down position of the squat the box helps to keep the squatter in form. Generally the squatter will maintain position just above the box in order to put additional strain on the muscles involved before returning to the up position.
Pistol squat: One of the more difficult of the body-weight squat variations is the Pistol squat. In the Pistol the squatter straightens one leg in front of them as they progress all the way to the down position of the squat. When the squatter reaches the down position the outstretched leg should be parallel with the ground.
Wall squat: The wall squat is an isometric variation of the traditional squat. Isometric means maintaining a static position during the exercise. While the box squat would be held for a moment or two before returning to the up position. The wall squat is maintained against a wall in the down position for the duration of the exercise. Wall squats should be held for at-least 15 seconds but more optimally for 1 - 2 minutes at a time.
Face the wall squat: The face the wall squat is an important variation to help with back problems and to help develop correct technique for weighted squats. In the face the wall squat the squatter should stand facing the wall feet an inch or two away from the wall, six inches to shoulder-width apart from each other. The squatter will then lower themselves to the down position, keeping their nose and forehead an inch or two from the wall similar to the distance the toes are from the wall.