Call me dumb, but I'm confused about the volume controls on my new iPhone X with ios 11. The side buttons change one volume and the slider inside the control center changes a different volume. How do I know which changes what? And does it depend on whether I'm just on the home screen or inside an app or watching/listening to media, or on a call, etc. How do I know which volume control does what at any given time? I've also always been confused by the ringer volume. Are there other sounds effected by ringer volume, such as alarms, etc. How do I know which sounds are effected by which volume controls?