What is M2M? M2M stands for machine-to-machine communication systems. It defines the communication between different machines without human intervention. The motivation for such a system of networked devices was prominent with the development of internet and wireless technologies. The first industrial sector to adopt M2M communications was the manufacturing factories and plants. However, these implementations were not 100% on par with the formal definition of M2M communication. Since, there was still human intervention in the processes, the definition of M2M needed zero human intervention. With the advancement of the internet, automation, and wireless technologies, the face of M2M transformed over the years. It also got expanded to many other sectors of applications such as healthcare, agriculture, and the automation industry. The Internet of Things (IoT) is one of the technological revolutions that appeared, which has roots in M2M communication systems. How M2M works? When considering the working mechanism behind M2M, communication mechanisms