There are many types of processors used in computer systems. A computer system is designed around its processor. The other electronics are designed for a particular type of processor.
Different processors have different machine operations.
This is why you ordinarily have to be careful to purchase the correct version of an application for your home computer. If you buy the game Myst, you need to get the version for whatever processor your home computer uses. But there is a version of Myst for both Pentium-based computers and for Apples. The answer is that even though the processors are different, the machine operations available on each can be used to build the same things. Both processor types have enough power in their little machine operations so that anything one processor can do with a machine program, the other processor can do with a different machine program.