The touch screen on the iPhone has a burden attached to it that more primitive mobile phones do not. The entire dynamic of cellular phone use, not to mention personal devices, has climbed to a new plateau. With this is almost endless options in terms of use and possible applications, but much of our more practical care of the device has not come that far. In this way, the touch screen can be an awkward annoyance that forcefully makes calls with the smallest accidental brush of the leg. Because of this, Apple has set it to have an Auto Lock function that prevents the normal iPhone desktop from being available at all times.
Instead, there is a base screen with a wallpaper graphic that you set and then you have to slide a bar at the bottom of the screen to open up the iPhone. This presents a double layer of protection that requires you to both hit the iPhone Home button and then slide the lock. Though this Auto Lock is an important iPhone function, there still is room to customize it to your exact specifications.