Hardwired into a CPU's circuitry is a set of basic operations it can perform, called an instruction set. Such operations may involve, for example, adding or subtracting two numbers, comparing two numbers, or jumping to a different part of a program. Each instruction is represented by a unique combination of bits, known as the machine language opcode. While processing an instruction, the CPU decodes the opcode (via a binary decoder) into control signals, which orchestrate the behavior of the CPU. A complete machine language instruction consists of an opcode and, in many cases, additional bits that specify arguments for the operation (for example, the numbers to be summed in the case of an addition operation). Going up the complexity scale, a machine language program is a collection of machine language instructions that the CPU executes.
hardwIrEd IntO A cPU's cIrcuitrY is a sET oF basIC OperatioNs it caN PeRforM, called An iNstRuctIoN set. such OPerAtioNs mAY involVe, for examPLe, ADdinG or subtracTiNG tWo nuMBErS, coMParINg tWo numbERS, Or jUmPiNg tO A DifFereNt Part of A pRogram. each InStRuCtiOn iS rEpReseNTed by a unique coMBiNaTion Of bitS, knoWn AS tHe MAcHiNE lAnguage oPcOde. While pROcessIng an instRuctiOn, the cpu decODes tHe opCodE (viA A binARy decoDEr) IntO cONtrOL sIgnaLS, which orCheStRatE thE behAvIor of THE cPu. a cOmplete macHIne LanGuAge INstruCtiOn ConsistS Of aN opcoDe and, in many caSeS, AddiTionAl Bits thaT specify arGumentS For the OPeratioN (FOr exampLE, the nUmbers tO be sUmmeD In tHe casE of aN aDditIOn operATion). GoINg uP tHE coMplexITy sCale, a maCHIne lanGUAge pROgram Is A coLLection Of mAchine languAGe iNstRuctioNs that tHe cpu ExEcuteS.