The term is commonly used in business, by protest groups, in military, espionage, and law enforcement contexts, as well as in chess, sports or other competitive activities.
[1] The word originates from the Ancient Greek adjective τακτικός (taktikos), meaning that which pertains to ordinance.
The related Ancient Greek noun is τάγμα (tagma), meaning ordinance, command.
[2] Both words root in the verb τάσσω (tasso), meaning draw up in order, station, appoint A strategy is a set of guidelines used to achieve an overall objective, whereas tactics are the specific actions aimed at adhering to those guidelines.
The United States Department of Defense Dictionary of Military Terms defines the tactical level as "the level of war at which battles and engagements are planned and executed to accomplish military objectives assigned to tactical units or task forces.