To the best of my knowledge, there is no general across the board consensus on the matter. Ask different age groups, people from different locations or regions and odds are they will all give you a different version. With that said, 40 years ago 200-225 was considered low and slow. Above 225-275 was considered hot. Anything over 275 was reserved for grilling for the most part. Fast forward a couple of decades and there is now people cooking in the 400 degree arena and higher. In my estimate, 200-225 will probably always fall into the "low & slow" category just for the fact that is about as low as most folks will ever cook. With the hot and fast trend steady making in roads with people, it's really hard to say where hot and fast now begins. Aaron Franklin is cooking around 300 and Myron Mixon as high as 375. If you compare this to the norm 40 years ago, they are both cooking pretty dog gone hot. Just for info, my take on it is as follows. 200-225 low and slow. 226-275 medium. 276+ hot and fast. Again this is just my thoughts on the subject. Soon some young new pit master will be showing us the new super hot and super fast method and throw a kink in everything all over again.