A thermistor is a type of temperature-sensing component that is composed of a semiconductor material. Thermistors are widely used in electronics and industrial equipment to accurately measure and monitor temperature. The most common type of thermistor is a negative temperature coefficient (NTC), which has a higher resistance value when temperatures are cooler and a lower resistance when they are warmer. Thermistors can be used to control temperature levels in a variety of electronic circuits, such as thermostats and in industrial processes. Additionally, they are often included in instrumentation to monitor temperature levels in various environments.