With a conventional fireplace, there isn't any way to control the amount of air that will feed the fire, thus it will burn almost uncontrolled and usually consume a great deal of wood. The actual control is how much fuel (wood) you feed it. And most of the heat that is generated will end up going out the chimney. You have a pleasant fire to relax and enjoy, and of course some heat, but it is terribly inefficient beyond the esthetic appeal.

Heat Travels in Three ways-Conduction, Convection, and Radiation. When a fire is built in a wood stove, conduction takes place as the heat moves through the stove body, or simply the heat moves through a solid material from a hotter to a colder area.

Convection occurs with the movement of heat through air(or fluids). Warm air rises and creates convection currents. As the stove warms up cold room air is drawn in through the stoves intake(s) at the bottom in most cases, heated and expelled through the stove body and in some stoves through vents. Sometimes a fan is used to accelerate the process, and heats the air.

When a Stove body heats up, heat is radiated into the surrounding area. Radiation here is the direct transmission of energy in the form of infrared rays that will heat the objects that they strike, though they don't heat the actual airspace surrounding those objects. Thus, when heating a room with a wood stove, you are heating objects, walls etc., not the airspace between them. A Basic wood stove heats by Radiant Heat.

With a wood stove, you can control the burn rate by either the damper control in the flue pipe(slows the burn and exhaust gases-smoke) or the actual amount of inlet air through adjustable controls on the stove, or more accurately, both, in conjunction with each other. Learning the correct balance of these controls is much like learning to sail a boat, all stoves are different as are all sailboats and Nature, and there is indeed a degree of expertise that is only accomplished by experimenting and learning from same what will give the desired result and efficiency you are looking for. Many folks will claim that their stove "Goes All Night!" but in reality, most good wood stove practices will yeild Good Coals to Restoke their Stove in the wee hours of the morning, not blazing away as the night before. Anyone claiming a 12 hour efficient burn with their stove is exaggerating, or burning Coal. Wood simply will not burn that long, and if it's smoldering slowly, you are indeed asking for trouble from excess Creosote forming in your stovepipe or chimney, a very dangerous thing. Creosote is the residual of unburned volatiles that can accumulate  when a stove is not burned efficiently, and can be a deadly thing resulting in chimney fires. Always burn your wood stove according to the Manufacturer's Recommendations, or in the case of an Antique Stove, use common sense. Don't try and stretch your burn time by over-dampening your stove, you'll simply not produce the heat you're trying to produce, and risk a potential chimney fire.