Due to advancements in technology with respect to wireless communication techniques (5G), advanced networks available, and reliable and fast hardware (sensors and actuators), there is a huge demand for IoT applications in various fields like smart homes, smart irrigation, healthcare, smart grids, advanced wearable devices, etc. Some of the IoT applications like healthcare, security surveillance, and industrial automation require high reliability as well as fast response. In time-constrained applications, cloud computing faces several difficulties like high latency, security, and network breakdown. To overcome these problems fog computing is a better option for the IoT applications which are time-constrained and require high security. In fog computing the data sent by the sensors used in IoT applications are processed and stored near the IoT devices. Depending upon the requirement of the IoT applications some of the data is processed in the fog layer and the rest of the generated data is sent to the cloud for processing and storing. In this review, we focus on the issues related to cloud computing and how they can be overcome using fog computing. In this study, we provide a thorough literature overview of fog computing. This review article categorizes newly released papers and examines the state of IoT applications using fog computing. We also covered the key traits of fog frameworks and identified a number of problems with their architectural layout, QOS measures, implementation specifics, uses, and communication methods.