RISC stands for "Reduced Instruction Set Computer". Originally, the idea was to make microprocessor chips that were less complex, so that they could be built smaller and run faster. Each instruction would take just a fraction of the time to execute, but more instructions would need be executed to accomplish the same task.

Although this might make things less convenient for the assembly language programmer, it was much simpler for a compiler to use effeciently. Indeed, this was the sort of thing that the designers of RISC were aiming for.

In addition to having fewer instructions, RISC chips supported some other interesting features. For example, all of their instructions are fixed-width.

As time as progressed, more and more instructions have been added to "RISC" chips, so that the original name is no longer accurate. Indeed, perhaps the only defining characterisitc betwen CISC and RISC chips these days is the fact that RISC chips use fixed-width instructions, while CISC chips use variable-width instructions.

RISC chips include such things as the Alpha, Power PC, and MIPS families.