Dual-band vs. tri-band routers: What's the difference between them?

Tri-band routers add a third wireless band—typically a second 5 GHz channel or a 6 GHz channel in Wi-Fi 6E/7 models—providing greater capacity and allowing one band to serve as a dedicated mesh backhaul. Dual-band routers use only 2.4 GHz and 5 GHz, offering longer range on 2.4 GHz but less overall bandwidth, which suffices for most homes unless multiple users stream, game, or video-call simultaneously.