An instruction in machine language. Its anatomy is a verb followed by one or more nouns:

     OP CODE    OPERANDS (one or more)
     (verb)     (nouns)

The op code is the operation to be performed (add, copy, etc.), while the operands are the data to be acted upon (add a to b). There are always machine instructions to INPUT and OUTPUT, to process data by CALCULATING, COMPARING and COPYING it, and to go to some other part of the program with a GOTO instruction. See hardware platforms and computer.