Wireless sensor networks are a group of specialized devices or sensors which are used to monitor different environmental conditions and to collect and organize that data at some certain central location.
It detects and measures a number of physical conditions such as humidity, temperature, sound, pressure, speed and direction, chemical concentrations, vibrations, pollutant levels and many other such conditions
A device which provides a usable output in response to specified event.
A sensor acquires a physical parameter and converts it into a signal suitable for processing. (e.g. optical, electrical, mechanical)
