I am new to iPhone and I find that none of the Apps (and the pre-installed Apps) have the choice of 'exit' or 'quit'. All I can do about exiting an App is to press the central Home button. However, I suspect that the program is still running background. 1. How to exit the program completely? 2. If I don't exit the program 'completely'. Will it consume more battery or memory running in the background? 3. If I don't exit the Camera completely, will the hardware components of the camera (e.g lens , something like that) be always ready for me and consume a lot of battery or aging it .