Since the iPhone 4, Apple has generally kept the SIM card slot in the same place on the handset on successive generations. You can find it on the right side of the phone, on the side opposite the mute ...

All modern iPhones and iPads now use nano-SIM cards. Unfortunately, this can be a bit of a problem for anyone switching from an older device, because the nano-SIM is much smaller than the micro-SIMs ...