Electronics: thermistors

Self-tutoring about electronic devices: the tutor mentions thermistors.

A thermistor is a device whose resistance is meant to vary with temperature. Some, called negative temperature coefficient (NTC) thermistors, decrease resistance with increasing temperature. Positive temperature coefficient thermistors do the opposite.

Thermistors can be used for measurement purposes or for circuit protection. Typically, NTC thermistors are used to measure temperature and/or change circuit behaviour according to it.

PTC thermistors, on the other hand, are typically used to protect circuits, which makes sense: if elevated temperature indicates too much current, one would want the resistance to increase in order to reduce current flow.

Such is my understanding.

Source:

dwyeromega.com