The Internet of Things (IoT) is a collection of objects such as sensors, actuators, and processors, which interconnected within a specific network to perform a task collaboratively. The IoT is one of the prevalent technologies, which has developed dramatically in recent years. Its reputation derives from its relevance and role in employing things in the best way, starting with smartphones that opened new horizons in control technologies and later developing new ideas regarding cloud-computing services. A smart gateway plays an essential role in the IoT applications that responsible for enabling communication between the network layer and the ubiquitous sensors network layer. IoT gateways are methods that operate with influential data centers as a point of communication between lower-end users. IoT gateways connect the heterogeneous devices in use and carry out many tasks to accomplish the computing mission. This work searches how IoT gateway's function and how they interact. In particular, it lists interface issues related to IoT gateways. In this paper, we research IoT and Smart Gateways and address Smart Gateways problems and computing techniques to promote IoT programs' stable transition to the Smart Gateway.