Simply put, a radio profile contains the settings that you apply to the radios in an AP. You would have one profile for 2.4 GHz radio and on for 5 GHz. Depending on the AP model, settings to tweak include mode, i.e. a/b/g/n/ac/ax, max transmit power, max clients. band steering, client load balancing, channel width, et al.
Here is the link to documentation for radio profile settings:
http://docs.aerohive.com/330000/docs/help/english/ng/Content/gui/configuration/configuring-radio-profile.htm
