Smoke Flow Type "Fire" vs "Fire+Smoke" In this question I showed images of a smoke simulation with Flow Type = Fire and Flow Type = Fire+Smoke. It seems that these two flow types have very little difference in their effects on the simulation. 

But I guess the developers had reasons to create those two flow types. What is the nature of these two flow types and how do these flow types influence the smoke simulation ? I also mean how do these flow types influence the voxel data / simulation fields (availability, strength) ?
So where do these flow types really have a different impact on your simulation ?
Flow type 

"Fire" -  lets the flame generate first and then the smoke is created when the flame dies off (depending on your settings). The smoke is generated FROM the FIRE not the mesh. 

"Fire+Smoke"- Generates fire AND smoke at the same time. Does not wait for the flame to die. The MESH generates the fire and smoke at the same time.