Command

The command pattern is a design pattern in which a request or action is encapsulated as an object, rather than expressed as a direct method call. That object bundles everything needed to invoke the action, so the caller need not know how, or even when, the action will actually be carried out.

It is encapsulation applied to a unit of behavior rather than a unit of data.

Separating the decision to invoke an action from its execution enables patterns like queuing commands for later or asynchronous execution, logging or serializing them for replay, and supporting undo by keeping a history of executed commands that can be reversed in turn.

It is one of the original Gang of Four behavioral patterns.