- An operation is a medical process, often opening the human body.
- The doctors performed the operation in three hours.
- An operation is an action of a group of people working for a goal (often military).
- The Army operation was a success.
- An operation is part or all of a business. (often plural)
- The company's East Coast operation was bigger than its West Coast operation.
- (mathematics) An operation is a symbol that is used to perform a specific operation (addition, subtraction, multiplication or division) in maths.
- The plus symbol is used to perform a specific operation in maths which is addition.