Overcooking

Overcooking is not when you have burned the pie or dried out the pork chops.  Conceptually it is the process of allowing foods to finish cooking outside of having direct heat applied in oven, grill or range.  To dig into the science Alton Brown style, the process of cooking is more than just making something hot/warm.  The structure of the material actually changes and mixtures combine differently at higher temperatures.  This is why raw meat changes color and stiffness as it cooks and also why you can 'cook' some things with acid as well as heat.  The mass of material also affects cooking process.  Finely chopped material cooks faster than larger chunks.  This is why cooking schools start by focusing on  getting consistent sizing of cut vegetables and have specific terms for sizes and shapes (i.e. diced, minced, cubed, batonette)  and this is where the delay of heat transfer comes into play. 

Think of a potato.  If you cut a potato into slices or fries, they cook up petty fast but to bake a whole potato takes much longer even for the same 'amount.'  Putting a potato into a cold oven and then turning it on makes that process take even longer than from a pre-heated unit.  If you take that same potato as you bake it and look at the temperatures in cross section, you would see the outside skin quickly spike in temperature while the inner core stayed cool for much longer.  Even after you take the potato out of the oven, heat is still traveling into the core and the cooking action is still happening.  THIS is what is called overcooking.  Large hunks of meat benefit from this technique most since you can avoid exceeding your preferred cook point (rare, medium ...) and retain the inner moisture.

Various strategies may be employed to convey heat to cook.  Using gas ranges and ovens gives the cook a faster temperature control than electric and pre-heating pans and ovens also start that heat transfer process faster than a cold start.  Using cooking stones and cast iron can slow the process of heat loss after the object is removed from the heat since the mass of these vessels retain heat very well.  Foil wrap and clean towels can be used to retain heat in a cooking object while it finishes off.  Some recipes will specify the method and timing of overcooking you need to use but so long as you make sure to cook meats enough to kill bacteria, it is something to experiment with.  So don't get insulted the next time someone tells you that you overcooked the ribs if you did it right.