Good question.
The more accurate way to look at smoking food would be the following:
Smoke itself does not cook but adds flavor, just think of the smoke like an additional seasoning to the meat, like salt, pepper, onion, garlic, or any other seasoning.
Heat cooks the meat not the smoke. Again smoke adds flavor.
So when we smoke meat we generally are doing two things.
- Cooking the meat with the heat that is generated via burning charcoal, gas, wood, or using electricity through a heating element
- Applying smoke to the meat for flavoring which occurs from smoldering wood, wood pellets, or wood dust. The smoldering of wood to apply smoke does not really add much heat to the mix because the wood isn't really burning up and causing a flame.
It can be a little confusing because people often use the word "smoking" to mean both cooking and applying smoke.
I always like to distinguish the difference between cooking and applying smoke because they are both actually different independent things.
For example, when I smoke bacon I cook until the internal temp (IT) of the meat hits 145F which usually takes around 12 hours BUT I apply smoke for only 6 of those hours. So to say I "smoked" bacon for 12 hours would be inaccurate, HOWEVER saying I smoked bacon where I cooked it for 12 total hours and applied smoke for only 6 of those hours would be 100% correct.
When someone says they "smoked" some meat they are kind of being ambiguous about how long they cooked the meat vs how long they applied smoke while cooking. Sometimes you apply smoke the whole time, sometimes you don't. The amount of smoke you apply all depends on what you are cooking and what you are trying to accomplish :)
Now when people "cold smoke" some meat it is simply to apply smoke flavor to the meat, not to cook the meat. This is often done with cheese, nuts, bacon, and some fish. Think about this. Why cook cheese when it is already ready to eat and applying heat would just make it melt away. Cold smoke cheese simply to add the smoked flavor.
Also with bacon people just want the flavor from the smoking and then they slice and fry the raw bacon in a skillet thereby cooking it :)
I hope I've explained this all well, if not let me know and I'll answer any additional questions or come up with better explanations until it is all clear :)