ZDNet:

The most important thing to understand about the role Arm processor architecture plays in any computing or communications market — smartphones, personal computers, servers, or otherwise — is this: Arm Holdings, Ltd. owns the design of its chips, and the architecture of their instruction sets, such as 64-bit Arm64. For its customers who build systems around these chips, Arm has done the hard part for them.

Apple Silicon is the phrase Apple presently uses to describe its own processor production, beginning last June with Apple’s announcement of the replacement of its x86 Mac processor line. In its place, in Mac laptop units that are reportedly already shipping, will be a new system-on-a-chip called A12Z, code-named “Bionic,” produced by Apple using the 64-bit instruction set licensed to it by Arm Holdings. Again, Arm is not the manufacturer but the designer of the processing cores and other on-chip parts. In this case, Arm isn’t the designer either, but the producer of the instruction set around which Apple makes its original design.

I don’t know if it’s everything you need to know but there is a lot of information here.