Machine-to-machine(M2M) refers to a network of connected objects. The network can be either a local network, a wide area network or the Internet. When these connected objects link to the Internet, they form the Internet-of-Things(IoT).
Connection between machines in the M2M sense means that these machines are able to send and receive information from each other through an M2M platform. This allows the machines to perform various tasks autonomously based on inputs received from each other, without needing human intervention.
Connection between these machines or objects can be achieved via a number of network technologies such as fixed broadband, cellular connectivity such as 2G, 3G, 4G or 5G, WiFi and dedicated IoT networks such as LoRa, Sigfox, Zigbee or LTE-M.
M2M communications is a key idea in Industrial automation and is expected to revolutionize manufacturing and other production processes that involve close interaction between machines.