wireless sensor and actuator network (WSAN) is a group of sensors that gather information about their environment and actuators, such as servos or motors, that interact with them. All elements communicate wirelessly; interaction can be autonomous or human-controlled.
WSANs are sometimes referred to as wireless sensor and actor networks because they can involve more than a single actuator on an actor point. An actor point might involve, for example, a combination of servos and multi-geared electric motors organized together to perform more complex tasks. A WSAN’s distributed sensors allow for automated measurement of environmental variables and control of some desired aspects of the environment through autonomous or directly controllable sensors and actors.

Disclaimer: As obtained from the Internet