As far as I know, a resistor and a heating element are the same thing. But one, the resistor, seems to limit the current in the circuit while the other, the heating element, draws more current and converts it to heat.
One wastes watts and the other doesn't, yet they are both resistors.
What is the difference between a resistor and a heating element?
They have most characteristics the same, but the OP is interested in the difference between them. Short answer: Thermal stability.
The major difference in characteristics between a resistor and a heating element is that resistors are designed from a material standpoint to have a low thermal resistance change. That is, resistors maintain as constant a resistance to current as possible throughout their operating range. Heating elements have no such requirement, so their resistance can and does vary a lot with current. For a lot of heating elements, its resistance will appear to be nearly a short at room temperature. As current goes through it and it heats up, its resistance increases.
A resistor and a heating element are indeed the same thing, just designed for different jobs. In a resistor, heat is generated as an undesired (but unavoidable) side effect, whereas in a heating element, the heat is exactly what it's supposed to do.
In fact, resistors can be used as heating elements! I've seen at least one ovenized oscillator (where a tiny oven is used to keep one component at a very specific temperature) that simply used a resistor as the heating element.
One difference that does exist, though, is that heating elements are generally made of materials that will work at higher temperatures. They're supposed to get hot, after all! Resistors usually aren't as heatproof.
A heating element is a resistor tuned to produce as much heat as possible when current is passing through it. When current passes through a resistor, there are losses defined as: $$P(Watt) = IR^2$$
Typically in a circuit, these losses are undesired and in portable electronics mean a loss of maximum battery life. So, in a heating element they are designed to produce as much heat per watt of loss in the resistor; in a conventional circuit, they are designed to have low of losses as possible.
