WSNPlanet.com

According to WikiPedia, a wireless sensor network (WSN) is a network made of many small sensor nodes (or motes) and one or more base stations (also called sinks), which centralizes the data gathered by sensor nodes.

Sensor nodes are small computers, extremely basic in terms of their interfaces and their components.

They usually only consist of a processing unit with limited computational power and limited memory, sensors (including specific conditioning circuitry), a communication device (usually radio transceivers or alternativelly optical), and a power supply. Other possible inclusions are energy harvesting modules, secondary ASICs, and possibly secondary communication devices (RS232, USB...).

The base stations are one or more distinguished components of the WSN with much more computational, energy and communication resources. They act as a gateway between sensor nodes and the end user.