Operation or Operations may refer to:

Science and technology

*Surgical operation
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical or dental specialty that uses operative manual and instrumental techniques on a person to investigate or tr ...

or surgery, in medicine
* Operation (mathematics), a calculation from zero or more input values (called operands) to an output value
** Arity
Arity () is the number of arguments or operands taken by a function or operation in logic
Logic (from Ancient Greek, Greek: grc, wikt:λογική, λογική, label=none, lit=possessed of reason, intellectual, dialectical, argumentati ...

, number of arguments or operands that the function takes
** Binary operation
In mathematics, a binary operation or dyadic operation is a calculation that combines two elements (called operands) to produce another element. More formally, a binary operation is an Operation (mathematics), operation of arity two.
More specif ...

, calculation that combines two elements of the set to produce another element of the set
** Graph operations, produce new graphs from initial ones
** Modulo operation, operation finds the remainder after division of one number by another
** Operations research, in British usage, application of advanced analytical methods to make better decisions
** Unary operation
In mathematics
Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathematical analysis, analysis). It ...

, an operation with only one operand
* Information technology operations
* Rail transport operations
Rail or rails may refer to:
Rail transport
*Rail transport
Rail transport (also known as train transport) is a means of transferring passengers and goods on wheeled vehicles running on rails, which are located on tracks. In contrast to r ...

, the control of a rail system
* Scientific operation
* Unit operation, a basic step in a chemical engineering process
* Inference
Inferences are steps in reasoning, moving from premises to logical consequences; etymologically, the word ''wikt:infer, infer'' means to "carry forward". Inference is theoretically traditionally divided into deductive reasoning, deduction and i ...

, a step in reasoning
Arts, entertainment and media

* ''Operation'' (game), a battery-operated board game that challenges dexterity * Operation (music), a term used in musical set theory * ''Operations'' (magazine), Multi-Man Publishing's house organ for articles and discussion about its wargaming products * ''The Operation'' (film), a 1973 British television film * ''The Operation'' (1990), a crime, drama, TV movie starringJoe Penny
Joseph Edward Penny Jr. (born 24 June 1956) is an English people, English-born American actor best known for his roles as Nick Ryder on the detective series ''Riptide (American TV series), Riptide'' from 1984 to 1986, and as Jake Styles in the Co ...

, Lisa Hartman, and Jason Beghe
* ''The Operation'' (1992–1998), a reality television series from TLC
* The Operation M.D., formerly The Operation, a Canadian garage rock band
Business

* Business operations, the harvesting of value from assets owned by a business * Manufacturing operations, operation of a facility * Operations management, an area of management concerned with designing and controlling the process of productionMilitary and law enforcement

* Military operation, a military action (usually in a military campaign) using deployed forces ** Black operation, or "Black op", an operation that may be outside of standard military protocol or against the law ** Clandestine operation, an intelligence or military operation carried out so that the operation goes unnoticed ** Combined operations, operations by forces of two or more allied nations ** Covert operation, an operation which conceals the identity of the sponsor ** Special operations, military operations that are unconventional * Operations (J3), third level of Nation Level Command Structure * Operations (military staff), staff involved in planning operations * Sting operation, an operation designed to catch a person committing a crime, by means of deceptionOther uses

* Operation, a word which represents a grammatical relation (i.e., function) or instruction, rather than a term or name * Anomalous operation, in parapsychology, a term describing a broad category of purported paranormal effects * Operation of law, a legal term that indicates that a right or liability has been created for a partySee also

* Operations support system, used in the telecommunications industry * Operations room, the tactical center providing processed information for command and control of an area of operations * List of military operations * OP (disambiguation) * Operative (disambiguation) * Operator (disambiguation) {{disambiguation