Its an Acronym, of course!
First, it is an acronym that is relatively simple: it stands for Machine To Machine (with 2 in place of the letter T). However, that acronym does not mean too much by itself!
Used more than a decade ago (and it is not exactly clear who said it first), the phrase and acronym has come to represent a variety of possible things.
For starters, in its most simple usage, it is the communication of data and control instructions from one machine to another over a network ... wireless or wired!
Examples of M2M Applications
M2M can mean the data sent by a device inside an automobile communicating (wirelessly in this case, of course!) to a computer system at a company ... that needs to know the information sent by the vehicle. Maybe an automobile has crashed and an airbag deployment notification is transmitted ... meaning that help needs to be sent to an injured driver.
Perhaps a cargo truck trailer has been filled, the doors are closed, and, now it needs to be picked up by a truck.
Or, it could be instructions sent by a computer system to a remote sensing device ... to ask it to send any telemetry and sensor data it has gathered. Perhaps, a gas pipeline pressure monitor system has to be read to determine if a drop in pressure has occurredgenerally implying a leak!
Often, such instructions are at the request of human usersaccessing the device via a web portal or running some dedicated programon a computer system networked to a service provider (like Aeris!) who delivers the commands and instructions to the devices.
The machine or device can be physically mobile (for example, a cellular unit installed in a truck or car) or physically fixed at a single location (for example, a residential security system or an automated meter reader).
Sometimes, one side of the M2M communications chain is a human. For example, it could be a special device operated by a human being that can read and send data to a computer system to serve a particular application purpose ... such as a home medical monitor transmitting blood pressure readings to a system where a Doctor can view the results for analysis.
Recent Terminology Expansion
Recently, the term has expanded beyond the concept of a single machine communicating to another machine. The term now includes the network and a system of communication, where data and control messages are sent from machines ... either to more machines ... or to humans!
In other words, as long as it isn't a traditional voice phone call (wireless or wired) between two or more human beings, it is probably an M2M application!