Nowadays, mobile devices have increased rapidly due to the fact that devices connected to the Internet become more portable and can respond to user requests remotely. With this increase, the workload of mobile devices has also increased. However, it is sometimes impossible for mobile devices with limited resources to evaluate some critical and large transactions locally on their own and hence, it may adversely affect the user experience. The MEC (Mobile Edge Computing) system, which enables these processes to be evaluated and returned to the device faster and more efficiently, is now made possible with the 5G-network technology. The MEC concept differs from the previous MCC (Mobile Cloud Computing) system. In this study, the content of the basic MEC system such as the comparison of the MEC system with the MCC, the advantages it offers to mobile devices, usage cases, offloading scenarios, effective resource allocation and mobility management are discussed. In addition, in the scope of the study, high performance studies using MEC system effectively in the literature were examined.