Crystals, Oscillators, Resonators(158193)

Definition:

Crystal, Oscillator, and Resonator products are devices used as sources or references for frequency generation and time measurement. Based in most cases on the physical vibration of some mechanical structure that vibrates at a known frequency, they are further classified along lines of their specific implementation and the degree to which additional supporting functions are incorporated, enabling convenience of use or higher attainable degrees of precision and/or accuracy.

What is the difference between a crystal oscillator and a resonator?

As for crystal resonators, they fulfill the same function, in that it vibrates mechanically when an electric current is applied to it. However, unlike the oscillator, which is an active device, the resonator is passive and the value of its impedance changes quickly over a narrow range of frequency.