A thermistor is a type of resistor whose resistance changes rapidly with temperature. The word 'thermistor' is derived from "thermal" and "resistor". They are temperature sensors.
Resistor is an electronics component that offers opposition to the flow of electrons. This resistance have a specific electrical resistance. Resistors are primarily used for current limiting, voltage division and similar functions.
The resistance of a resistor is measured in ohms using the Greek symbol omega (Ω).