Power over Ethernet is a standard that sends electrical power and network data through the same Ethernet cable. Instead of using a separate power adapter, devices such as IP cameras, wireless access points, VoIP phones, and some sensors can run from a PoE-enabled switch or injector. This simplifies installation, reduces cable clutter, and makes it easier to place devices where outlets are unavailable.
PoE matters in cyber security because it ties power and connectivity together. If a PoE switch, injector, or cable is damaged or misconfigured, the device may lose both network access and power at once. In attacks, cutting, unplugging, or disabling PoE can knock offline cameras, phones, or access points. In defense, administrators monitor PoE budgets, cable integrity, and physical access to switches so critical endpoints stay powered and reachable.