A set of instructions in AssemblyLanguage

http://www.computerhope.com/jargon/i/instset.htm
* The instruction set, also called instruction set architecture (ISA), is a part of the computer that pertains to programming, which is basically machine language. 
* The instruction set provides commands to the processor, to tell it what it needs to do. 
* The instruction set consists of multiple pieces, including addressing modes, instructions, native data types, registers, memory architecture, interrupt, and exception handling, and external I/O.
* An example of an instruction set is the x86 instruction set, which is common to find on computers today. 
* Different computer processors can use almost the same instruction set, while still having very different internal design. 
** Both the Intel Pentium and AMD Athlon processors use nearly the same x86 instruction set. 
* An instruction set can be built into the hardware of the processor, or it can be emulated in software, using an interpreter. 
** The hardware design is more efficient and faster for running programs than the emulated software version.