Here ya go:
With DSC on, the car modulates the throttle to kill 99.9% of any wheel spin. This is the standard mode.
With DTC on (push button briefly), the car will allow most forward wheel spin, but if it detects side to side movement, it will cut power.
With DSC completely off (hold button for 4 seconds) it will allow any wheel spin.
Most of the time you should just be in the normal DSC mode. For winter/slick driving sometimes turning on DTC is helpful so you can get moving. DTC is a subset of DSC.