Origins
The word "command" entered English around 1290 from Old French "comander" (to order, to instruct, toβββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ entrust), from Late Latin "commandΔre" (to recommend, to entrust with emphasis), an intensified form of Classical Latin "mandΔre" (to commit to someone's charge, to order). The underlying compound is "manus" (hand) + "dare" (to give), with the prefix "com-" (together, with) serving as an intensifier. A command is, at its etymological core, a mandate given with full force β a task placed into hands with unmistakable authority.
The relationship between "command" and "mandate" is parent and child. "Mandate" preserves the bare Latin form: to place in the hand. "Command" adds emphasis: to place in the hand forcefully, urgently, with the full weight of authority behind it. This difference in intensity persists in modern usage β a mandate is an authorization, while a command is a direct order. One can decline a mandate; one disobeys a command at one's peril.
The word generates a rich family. A "commander" is one who gives commands. A "commandment" is a formal command, especially a divine one. The "Ten Commandments" are literally the ten things placed in human hands by God β divine mandates of the highest authority. "Commandeer" (to seize for military or public use) extends the authority of command to the taking of property. "Commando" β borrowed from Afrikaans during the Boer War (1899-1902), which took it from Portuguese "comando" β refers to a raiding unit or a soldier in such a unit, a specialized agent of military command.
Development
In computing, a "command" is an instruction to a computer β a direct order to the machine. The "command line" is the interface where a user types commands directly, without the mediation of graphical elements. This usage preserves the word's etymological force: a command is not a suggestion or a request but a directive that must be executed. The computer, unlike a human subordinate, obeys every command literally and without interpretation β making the command-line interface simultaneously the most powerful and the most dangerous way to operate a machine.
The military sense of "command" encompasses both the act of commanding (giving orders) and the domain of command (the forces and territory under one's authority). A "command structure" is a hierarchy of authority. "Chain of command" is the sequence through which orders pass from the highest to the lowest rank. "Command and control" (C2) is the military doctrine of exercising authority over forces. The Pentagon's "combatant commands" divide the world into geographic and functional domains, each under a four-star general or admiral.
The phrase "to command a view" (of a height or position that overlooks a landscape) preserves an older military sense: a fortification that "commands" a valley has authority over it β it can see and therefore control the terrain below. This spatial metaphor links visual dominance to military authority.
Latin Roots
The sibling words "demand" and "recommend" share the same Latin root. "Demand" (from "dΔmandΔre," to give away fully, to entrust completely) means to ask with authority β to place a claim in someone's hand that expects compliance. "Recommend" (from "recommandΔre," to entrust again, to commend to someone's attention) means to present favorably β to place something in someone's hand with a personal endorsement. "Countermand" means to cancel a previous command β to take back what was given to the hand.
The evolution from "manus" (hand) to "mandΔre" (to place in the hand) to "commandΔre" (to place in the hand with force) to modern "command" traces a progression from physical gesture to abstract authority. The original act β one person placing an object into another person's hand β became the central metaphor for delegation, obligation, and power. When a general commands an army, a king commands a nation, or a programmer commands a computer, they are all performing a version of that ancient gesture: placing a task in hands that must execute it.
From the Ten Commandments to the command line, the word encodes the most basic model of authority: one who gives and one who receives, with the hand as the point of transfer.