What technology supplies electrical power from a switch port over an ordinary data cable to a powered device?

Power over Ethernet (PoE) is the technology that allows electrical power to be transmitted along with data over standard Ethernet cables, such as Cat5e or Cat6. This capability is particularly useful for powering devices like IP cameras, VoIP phones, and wireless access points without the need for additional power sources or separate power cables.

By utilizing PoE, network devices can receive power directly from the network switch or injector that is connected to them via the same Ethernet cable that provides data connectivity, thus simplifying installation and reducing the amount of wiring required in a network setup. This technology adheres to IEEE standards such as 802.3af and 802.3at, which define the requirements for delivering power over Ethernet.

The other options do not involve supplying power over data cables. A Network Interface Card (NIC) is a hardware component that enables a device to connect to a network but does not provide power. Ethernet over HDMI refers to a method for sending Ethernet signals over HDMI cables, which is not related to powering devices. A wireless access point is a device that enables wireless connectivity to a network but does not itself provide power over Ethernet.