An operation is a named specification of a service that can be requested from any object of a class to affect behavior. It is a specification of a query that an object may be called to execute.
An operation can be created for a class or interface in the following diagrams:
A class may have any number of operations or no operations at all.
In the following example, the class Car, has 3 operations: start engine, brake, and accelerate.
Operations have a name and a list of parameters. Several operations can have the same name within the same class if their parameters are different.
For more information on EJB operations, see Defining Operations for EJBs.