Like others have said, temperature control just limits the temperature of the coil(s). This provides a consistent hit every time and also prevents dry hits.
With the wattage vaping that is the norm now, all the mod is doing is sending power to the coil. The longer this power is applied to the coil, the hotter it gets. If you take rapid and/or long hits, the temperature of the coil will keep increasing as power is being sent to the coil. This is what causes a burning hit sometimes. If you have really sensitive taste, you may even notice that some hits are better than others. This is because the temperature of your coil isn't being regulated and one hit may be at 200F, the next 370F, the next 490F, etc.
Temp control will send power to the coil until the coil reaches a certain temperature. Once it reaches the desired temp, the mod will turn the power off and on to keep the temperature of the coil to what the user set it to. This will provide consistency in every hit, prevent the vape from getting too hot, and even prevent dry hits.
It's more of a luxury thing right now as it's still being developed. I personally think it isn't worth the money right now.