A back handspring is begun standing, normally with the arms stretching our in front. You then swing your arms and jump back onto your hands, pull your legs over and landing on your feet again. This skill is to be done FAST!
From a bridge (or back bend) position, you jump with your feet and legs together and pull your legs over your head landing on your feet. Your legs should never come apart in this skill.
From a bridge (or back bend) position, you kick your legs over your head and land on your feet in a lunge.
From a standing position with your arms straight by your head and looking up at your hands, you bend you back in a "U" shape, putting your hands on the ground so that you are in a bridge.
In a bridge, you start by laying on your back, and placing your hands next to your head with your fingertips pointing towards your toes. You then bend your legs and place your feet on the floor and push with your arms and legs so that your arms are straight and your head is off the ground.