NTC 2k2 is a resistor, which significantly changes it's resistance with temperature (R decreases as T increases). 2k2 at room temperature (25C), around the value of the most widely used ones in the automotive industry (GM, Honda, etc...). The default tables of genboard firmware (that can be changed, of course) almost match these. They fall to in the 100 Ohm range at 100C, and even lower at higher Temp. Usable for about 150C. Above 150C (EGT, head-T of hot engines), the thermocouple is used (which is much more costly and harder to measure, but more linear) for measuring temperature.
The MAT and CLT sensors of most cars are this component packaged for easy mounting to a particular engine. This can be mounted with epoxy glue. (except when mounted on board for measuring in-case-temp).