PPC is built on the RISC architecture, while Intel is founded on the CIISC architecture. PPC cannot run modern desktop operating systems while Intel is capable. The more modern computers can have Intel processors, while PPC is used in embedded applications. PPC and Intel differ based on the architecture each possesses.
PPC has more straightforward instructions because of the RISC architecture. It only needs one direction to perform. When PPC was first introduced, it provided a better alternative to Intel. Several popular operating systems were ported to it. On the other hand, Intel has implemented the CISC architecture, which is far more complicated than PPC.
Intel rendered the PPC obsolete. To this day, Intel is still on top as far as computer microprocessors are concerned. However, there has been significant buzz centered around the idea that PPC makes a comeback.