In the modern world, manufacturing has advanced to the point where it is now driven more by data and intelligence. One way to think about a smart production unit in this day and age, with the advent of the Industrial Internet of Things (IIoT), is as a highly efficient and interconnected industrial system that is made up of materials, parts, equipment, tools, inventory, and logistics that are all able to send and receive data and communicate with one another. This is one way to conceptualise a smart production unit. The term IIoT refers to networked devices, sensors, and other pieces of equipment that can be networked in an industrial setting to allow for remote access, efficient monitoring, improved data collection, analysis, and exchange, and other benefits along the same lines. The IIoT is significant in the context of Industry 4.0 for the transformation of cyber-physical systems (CBS) and industrial methods through the use of big data and analytics. This chapter provides an introduction to the technologies that support the IIoT as well as a general overview of the IIoT. In addition to that an in-depth overview of the primary benefits and characteristics of IIoT in manufacturing is presented.