The difference between the two frequencies on your business WiFi are the range (coverage) and bandwidth (speed) that the bands provide. The 2.4 GHz band provides coverage further away but transmits data at slower speeds. The 5 GHz band covers less distance but transmits at faster speeds.
So, if you need higher performance or speed, the 5GHz band should be used. It’s the newer of the two and has more channels for communication, and usually there aren’t as many competing devices on the newer band. The 2.4GHz band is more prone to interference because of the number of devices that use this frequency. This includes older routers, microwaves, Bluetooth devices, monitors and more. It’s worth noting though that higher frequencies cannot penetrate solid objects, such as walls, so you need to factor this into using your 5GHz.
It’s a good idea is to spread out your office devices over the two bands so that there’s less competition for the same channels.