Define the term Computer architecture and Computer organization.

Computer architecture means the attributes of a computer that are visible to the programmer. It includes the instruction set, the data formats, the addressing modes, the registers and the I/O methods. It decides what the machine can do.

Computer organization means how these features are actually built in hardware. It deals with control signals, the interfaces between units, the memory technology and the data paths. It decides how the machine does it.

For example, a multiply instruction is architecture. Whether it is done by a separate multiplier circuit or by repeated addition is organization.