Industry 4.0 refers to the phase of transition that is taking place, enabling automation and data interchange in industrial technologies and processes. Fog computing architecture can provide real-time processing, nearby storage, extremely low latency, dependability, large data rates, and other requirements for industrial Internet of Things (IIoT) applications. In the context of IoT applications, fog infrastructure and protocols are the main areas of interest. The phrase “fog computing,” sometimes known “edge cloud,” is a new paradigm. Between edge devices and Cloud Core, it adds another layer. Along with providing computing, storage, and networking capabilities, it also fills a need left by the cloud. The main features of fog computing are covered in this chapter, along with current research on the subject and a focus on the difficulties encountered when creating its architectural design.