DM types

[Storm Bringer]

The Uncreative (working title, adjust if needed)
"the door on the LEFT?.......it's, errrrr....locked. Yhea, locked. No, you can't pick it. No, Knock doesn't open it. why not try the door on the RIGHT?"
When he's got a pregenerated/prewitten adventure on hand, he is a decent DM, with a firm grasp of the rules and player management, and all is well.

He just....isn't to hot on the whole improvising thing. While things are in the bounds of his planning, he's fine. but he needs to make stuff up on the spot, he panics, backtracks, does what he can to get the plot on the lines he thought about. Sort of like railroading, with very wide rails.

The Wargamer
"Ok, thier is a Panzer 4, model 1943 late production type, with maybe a squad of Panzergrenadiers with it, armed with MP40s and a panzerschreck, here, by the woods. A MG, 34 or 42, you can't tell, is in the guardhouse amd covering the road........"
The DM equivelent of a roll-player. Sees the game as a tactical simulator frist, rp platform last if at all. This is more of a style thing, and with a group of like minded players he is right at home and everyoen has fun. It's only when a dedicated RP type joins the group that trouble occurs, as the Rp'er gets bored with the long stretches of combat unbroken by plot breaks.

The freeformer
You meet a dragon. What colour? er....Let go with Blue, we've not had one of those for a while.

Makes it all up as he goes. No planning, no arcs, just gives the players a hook sees where they go and runs with it. if done well, it leads to superb games fillied with very memoerable moments and the players feeling that they are uncovering a very complex planned adventure. If done badly, leads to a muddle as the players stuble blindly about, unfocused on any goals and someone unenthused.

the above a based VERY loosly on some DM's I've played under, with traits exaggerated for Illustration purposes.