Power Over Ethernet (PoE): Theory, Design, and Best Practices is a comprehensive guide exploring the principles, standards, and practical deployment of PoE technology across modern networks. Covering everything from foundational electrical concepts to advanced design strategies for enterprise, industrial, and smart infrastructure environments, this book equips readers with the knowledge to implement reliable, efficient, and scalable PoE systems. It bridges technical detail with real-world application, offering insights into standards like IEEE 802.3af, 802.3at, and 802.3bt, while addressing critical topics such as power budgeting, safety, thermal considerations, and integration with existing network and power infrastructures.