An instruction is an order given to a computer processor by a computer program. At the lowest level, each instruction is a sequence of 0s and 1s that describes a physical operation the computer is to perform. Instructions can vary in length, from a few bits to many bytes. They can also specify special storage areas called registers that may contain data to be used in carrying out an instruction. Instructions also specify the location in computer memory of the data and the input/output (I/O) format to be used. A collection of computer instructions is an instruction set, which facilitates a variety of tasks for a computer systems central processing unit (CPU) to execute.
Outside of computing, an instruction can refer to something that someone tells you to do, such as an order or direction calling for compliance. It can also refer to advice and information about how to do or use something. In education, instruction refers to the transfer of learning from one person to another.
