In recent times, smart devices, smart homes, smart manufacturing, and even smart cities, all of which are connected to the Internet of Things (IoT) have become quite common. IoT technology heavily relies on Machine-to-Machine (M2M) communication in order to make all smart technologies behave in a smart way. Any type of connection between two devices that does not require human intervention is referred to as "machine-to-machine" communication technology. The IoT is a system of devices with unique identifiers that can transmit information over a network. There is no interaction between humans or machines in the IoT. The IoT is now widely used in a variety of sectors, including banking (connected branches), and industries where secrecy and privacy of data are the important components. The IoT allows multiple machines to design a connected data network, whereas M2M makes it possible for devices to communicate with one another. Therefore, this paper gives a brief review work on security challenges faced in the connection between IoT and M2M communication and the significance of both technologies.