Architecture license means you can use the ISA (provided by Arm). Micro arch means you can license the core implementations form Arm. Apple is an ISA license, meaning they have full control of the micro arch as long as it passes verification by Arm. That’s the beauty of Arm, you get rid of the problem of creating the whole software ecosystem...it’s already there, and companies like Cavium, Apple, Qualcomm are free to add their secret sauce and benefit from the mature software environment. At least, that’s the hope.