A wireless sensor network (WSN) consists of inexpensive power constrained sensor nodes collecting data from the sensing area and transmits data towards the base station in a synergetic way. Wireless sensor networks are appearing as an emerging need for mankind now a day. The basic goal of Wireless sensor networks is to enhance the lifetime of the network, and to use the energy of nodes efficiently. The WSN nodes are restricted by energy, storage capacity, and computing power. So it is necessity to design more effective and energy aware protocols to enhance the network lifetime and stability. Energy efficient design and implementation of WSN has become a very popular area of research in recent years. Increasing the stability and network lifetime is the major issue in WSN. This paper presents a review on different protocols of wireless sensor network.