Wireless sensor network is the collection of mobile or static nodes which are capable of communicating with each other in order to collect data accurately, autonomously. The wireless sensor network has number of applications but data gathering is the major application in which wireless sensor network is used to periodically collect data from sensor field. Various numbers of protocols are used in order to maximize life time by efficient use of energy. Direct transmission, binary scheme, LEACH, PEGASIS is discussed in this paper. LEACH communicates by using cluster heads and PEGASIS involve leader selection.