Command has multiple meanings:

• An order.
• In organizations, a command is an office or position of authority.
• In telecommunication, the term command has the following meanings:
  • An order for an action to take place.
  • In data transmission, an instruction sent by the primary station instructing a secondary station to perform some specific function.
  • In signaling systems, a control signal.
  • In computer programming, that part of a computer instruction word that specifies the operation to be performed. See command (computing) for detail.
  • Loosely, a mathematical or logic operator.
• In computer programming, command pattern is a design pattern.
• The command key is a modifier key on Apple Macintosh keyboards.

References

• Federal Standard 1037C
• MIL-STD-188