The i386, ARMv6, ARMv7 and ARMV7S are processor architectures (instruction sets), the ARMv7S is found in the iPad 4 and iPhone 5 (with the Apple A6 processor).
The Apple designed processor A6
is the first one to be of the ARMv7S architecture. It's fully ARMv7 compatible, but has some specific optimalisation added by Apple. These optimalisation will not work in normal ARMv7 that is why they added the s.
Wikipedia calls it Switft and AnandTech has a nice post about:The iPhone 5 review - Decoding Swift