Operation

the state of being in effect or being operative

a business especially one run on a large scale

a planned activity involving many people performing various actions

(computer science) data processing in which the result is completely specified by a rule (especially the processing that results from a single instruction)

activity by a military or naval force (as a maneuver or campaign)

a medical procedure involving an incision with instruments

a process or series of acts especially of a practical or mechanical nature involved in a particular form of work

process or manner of functioning or operating

(psychology) the performance of some composite cognitive activity

(mathematics) calculation by mathematical methods

the activity of operating something (a machine or business etc.)