Now is the Internet era, especially the Internet of Things era. Nowadays, the Internet of Things has become an important part of the new generation of information technology. In this information age, the interconnection of all things is an important stage, and the interconnection of all things is the common goal of everyone.

  In fact, the concept of the Internet of Things is based on the Internet, not formed independently. It is a process of mutual learning and integration in various fields. However, different information fields have different views on the Internet of Things, and all walks of life have their own perceptions and ideas. Even today, there are still great differences in the understanding of the Internet of Things in various fields, and even have their own appellations. There are three clear definitions: "M2M", "IoT" and "CPS". What is the difference between these three concepts?

  M2M (Machine to Machine)

  The concept of "M2M" is mainly put forward by the communication industry. Firstly, M2M mainly refers to the communication between mechanical equipment without information capability and other equipment or information systems (information technology systems) through mobile communication networks (wireless networks).

  The communications industry believes that after meeting the needs of communication between people, the network can also allow "machines to come". Machines and machines to form more efficient information applications. Since then, the concept of M2m has expanded to "man-to-machine" or "machine-to-man".

  Generally speaking, M2M refers to people, devices and information systems, as well as the information exchange and interaction between them.

  The concept of M2M mainly emphasizes the realization of communication, and the network is the core of its technical framework. The reliable connection of "wireless connection" is realized by "end-to-end" technical means. On the basis of the "connection" between the Internet of Things and the Internet of Things, it can realize centralized asset monitoring, remote operation of equipment, logistics warehouse management, mobile payment and other applications.

  IOT（Internet of Things）

  The IT industry thinks the concept of the Internet of Things dates back to Xerox's Internet-connected Coke machines in 1990.

  Then, in 1999, the MIT Center for Automatic Identification proposed the concept of Internet of Things based on RFID technology, and emphasized the concept of "information sensing devices connected to the Internet" in its definition. (The definition of the original RFID Internet of Things: All items are connected to the Internet through information sensing devices such as radio frequency identification to achieve intelligent identification and management.)

  So far, the Internet of Things is a concept of the Internet of Things promoted by Internet enterprises, software enterprises and even the entire information industry. After realizing the social interconnection between people, Internet companies hope that things can communicate with each other through the Internet. The foundation of the Internet of Things is still the Internet, which is the extension and development direction of the Internet.

  The concept of Internet of Things mainly emphasizes Internet interaction, and the globalization, openness, interoperability and sociality of the Internet are the basis for supporting the concept of Internet of Things. Once smart products have "network identity", they can derive various Internet applications: product leasing (sharing smart products), information services (such as location services, electronic payment, big data analysis), wearable product applications and so on.

  Network physical system

  In 2006, Helen of the National Science Foundation

  Gill proposed the concept of CPS and listed it as an important research project. Because CPS focuses on the research of embedded and automated information systems in industry and manufacturing, it was initially intuitively understood as "embedded Internet of Things" (from the perspective of information industry, this understanding is somewhat one-sided).

  In "Network Physics"

  In the term "system", "Cyber" refers to an information system and "Physical" refers to a physical system (equipment, environment, and generated data).

  CPS emphasizes the real-time dynamic information feedback and circulation process between the physical world and the information world.

  It deeply integrates sensors, embedded computing, cloud computing, network communication, software and other information technologies, so that various information capabilities (3C: computing-computer, communication-communication, control-control) are highly coordinated and autonomous, and the independent, intelligent, dynamic and systematic monitoring and change of the physical world are realized.

  CPS has a wide range of applications: from tiny nano-robots to huge engineering infrastructure equipment, from urban traffic information to remote surgical medical systems, transportation, medical treatment, agriculture, energy, national defense, construction, manufacturing lines are all its fields. At present, CPS pays more attention to scientific research, while M2m and Internet of Things pay more attention to the landing of engineering technology.

  In industry, production systems receive and process feedback information (perception) from the physical world while operating mechanical equipment. The "upload" and "release" information in the production operation has a high degree of real-time synergy.

  In the three concepts of "M2m", "IoT" and "CPS", CPS is designed to meet this feature, so it is recognized as the Internet of Things (IIOT) in the industrial field and the basic information system of the next generation industrial system.