Ethernet cables are often seen as simple internet connectors, but they can also carry video, audio, and power. The source notes that with the right adapters, category cables like Cat5e or Cat6 can transmit video over longer distances than typical HDMI cables. This requires HDMI extenders at each end, and the setup is not true Ethernet networking—it just uses the cable as a signal carrier. While handy for reaching a distant projector or using existing in-wall wiring, it may not beat active optical HDMI for high-end formats like 4K at 120Hz.
For audio, the same cables can replace multiple analog cable runs. With appropriate adapters, a single category cable can carry several channels, which could connect microphones in one room to recording gear in another. The source points out that standard XLR cables are often easier and cheaper, but category cable becomes clever when the wiring is already in place. Shielded cable may be needed for setups where microphones draw power through the connection.
The most genuinely useful application is Power over Ethernet (PoE). This standard lets one Ethernet cable deliver both data and power, making it ideal for security cameras, Wi-Fi access points, and other devices far from outlets. The cable simply needs to connect to a PoE-compatible switch or injector. Unlike the video and audio tricks, PoE is a practical, widely adopted solution—though equipment must support it and supply enough power for the device. The source's overall message: these extra uses are possible, but not always the best choice for every situation.