Software Defined Networking is an adaptable way of networking, which disconnects data forwarding plane and controlplane of system equipment's and also solves issues in existing network infrastructure. More specifically, the control-plane of software defined network decides the advancing way of network flow with Centralized Control Manner (CCM). SDN (Software Defined Networking) is a strategy for making, planning and overseeing systems which intend to change this present unfortunate circumstance. It has been used in dissimilar areas, like a campus networks and data center systems. In this survey paper, we've reviewed the concept of (SDNs) Software Defined Networks, its architecture and applications. In the survey, it h as been found that SDN load balancing has become more smart and efficient and reduces the statistic collection overhead and maintain better QoS (Quality of Service) data rates. In addition, we reviewed the direct routing based algorithms of Load Balancer and compare with Round Robin Strategy. Furthermore, we've reviewed and compared the existing work to get better idea about the concept of Load balancing.