Modern industrial grade network switches ensure seamless connectivity and power in factory automation environments. This article will systematically review the core knowledge of industrial switches from three dimensions—classification logic, technical characteristics, and application scenarios—and analyze their selection logic. There are a variety of styles, sizes, and types of network switches available. Normal and industrial switches can vary in working temperature. Hierarchical Levels Industrial Networks align device, control, and enterprise layers across PLCs, SCADA, MES, and ERP, using fieldbus, Ethernet/IP, and Profinet to ensure deterministic control, real-time data, cybersecurity, and scalable OT-IT integration.