5G is the next step in the evolution of mobile communication. The evolving 5G cellular wireless networks are envisioned to provide higher data rates, enhanced end-user quality-of-experience (QoE), reduced end-to-end latency, and lower energy consumption. Device to device (D2D) is one of the key technologies provided to enhance 5G performance. Direct communication between two devices without involvement of any central point (i.e., base station) is defined as device to device (D2D) communication. It is a recommended technique to enhance the network performance of 5G in terms of energy efficiency, throughput, latency, and spectrum utilization. In this chapter, the authors provide a detailed survey on the integration of D2D communication into cellular network especially 5G network. The survey highlights the potential advantages; classifications and application for D2D technology have been indicated. Main D2D standards have been presented. Finally, the chapter addresses main topics that could be related to D2D and indicates all major possible challenges that face most researchers.