This new Modern era is full of various new and promising technologies which are capable enough to change the entire world within the fraction of a second. Wireless Sensor Network is the one which is going to play the vital part in this modern scenario. This particular technology shows some great promising feature for the various sector like military as well as public. Combined with various other technology it can be sufficient to solve many problems arising day by day. But like all the other technology it lacks in some fields. In this paper we will try to review this technology as well as issues and security requirements.