In this paper, a survey on Wireless Sensor Network (WSN) and their technology, standards, prototype and applications was carried out. A wireless sensor network consists of thousands of inexpensive miniature devices capable of computation, communication and sensing. It provides a bridge between both the real and virtual worlds. Allow the ability to observe the previously non-observable at a fine resolution over large spatio-temporal scales. Have a wide range of potential applications to agriculture, health, transport system, disaster detection and defense. This paper supports the difficulties of operating such sensor network in the most hostile environments.