How to Use your back button focus & why

Do you have a SLR and yet you feel that you are missing out on some features? Let's check out the back button focus. When you press the shutter button half way, it moves the focus to the back button. One can activate their camera's focus while the taking the picture which pretty much becomes a manual mode but gives you a lot of independence while taking pictures and it helps keep your subject in focus. This will benefit in taking pictures of high contrast.