The functioning of a CPU, also known as a computer chip, involves many secondary aspects--the voltages and currents that are required, the cooling arrangements that are in place to prevent the chip from overheating, the proper functioning of ancillary devices, and so on. However, in bare terms, the features of the CPU itself may be stripped down or abstracted to just the instruction set it implements. An instruction set is the set of basic "instructions" or programmer-visible commands that a chip can carry out directly. A chip that has a specific instruction set has to be given orders that are instructions from that instruction set; complex commands must be broken down into sequences of instructions from that set.

To see what an instruction looks like, consider the following list of instructions, which are among those implemented by the 80x86 family of processors (the predecessors of the...