M2M and IoT are very similar technologies, but there is a significant difference:
M2M: It is a general concept involving an autonomous device communicating directly to another autonomous device. Autonomous refers to the ability of the node to instantiate and communicate information with another node without human intervention. The form of communication is left open to the application.
It may very well be the case that an M2M device uses no inherent services or topologies for communication. This leaves out typical internet appliances used regularly for cloud services and storage. An M2M system may communicate over non-IP-based channels as well, such as a serial port or custom protocol.
IoT: The ecosystem starts with the simplest of sensors located in the remotest corners of the earth, and translates analog physical effects into digital signals. Data then takes a complex journey through wired and wireless signals, various protocols, natural interference, and electromagnetic collisions, before arriving in the ether of the internet. From there, packetized data will traverse various channels arriving at a cloud or large data center.
Before cloud technology and mobile communication became mainstream and cost-effective, simple sensors and embedded computing devices in the field had no good means of communicating data globally in seconds, storing information for perpetuity, or analyzing data to find trends and patterns. By moving data onto the internet for sensors, edge processors, and smart devices, the legacy world of cloud services can be applied to the simplest of devices. As cloud technologies advanced, wireless communication systems became pervasive, new energy devices like lithium-ion became cost-effective, and machine learning models evolved to produce actionable value.
The strength of IoT is not just one signal from one sensor, but the aggregate of hundreds, thousands, potentially millions of sensors, events, and devices. IoT system architects and designers must be able to speak to the value the design brings to a customer. The system architect and system designer must also play multiple engineering and product roles in balancing different design choices.
Unlike IoT, which is a network of multiple sensors and devices, M2M is a connection between two devices. This allows for end-to-end encryption so a malicious party would have to connect to one of the devices directly. M2M connected machines may not have any other connections, so even if one of the machines was compromised it might not grant access to a larger network of devices.
End-to-end encryption, or E2EE, is a secure communication method that encrypts the data being transferred. Only the participant is able to decrypt the data. This means that third parties that might monitor the connection can only see encrypted packages, but not their contents.
The terms M2M and IoT can seem like the one and same, but there are some key differences. Watch the video below to get a better grasp of the differences and similarities between the two.