What Are The Differences Between 2.4 Ghz and 5 Ghz?
David Coleman (CWNE#4 and distinguished networking books author) and Gregor Vucajnk (CWNE#96 and Director of Product Training at Aerohive networks) discussing the differences between 2.4 GHz and 5 GHz WiFi band.
While not dead, 2.4 Ghz isn't near as useful. It only had 3 non-overlapping channels. Due to this, co-channel interference is almost impossible to avoid. With 5 Ghz, Wi-Fi deployments have much more flexibility with capacity and channel width.