Both can be used by setting your devices to use 2.4 or 5GHz. That way you get the most out of your air space since one device will be on one channel and the other on the other channel. WiFi space normally was a shared space for 2 devices. Now you can get your own channel.

But if you are asking how to bond channels, you end up running some Linux system, getting two WiFi sticks and learning far more than any of us.