A quartz crystal has some special properties, and it provides the basis for timekeeping in most modern clocks and watches.
A very small electric current can be used to make a quartz crystal vibrate. Anything that vibrates tends to have a special vibrating rate, or frequency, that it “likes” best. A frequency that I have read about for a particular shape of quartz crystal is 32,268 times per second. That’s very steady and not much affected by temperature changes. So it makes a good basis for keeping time.
Of course no one can count that many vibrations per second. But an electronic counter can advance a watch one second for every 32,268 vibrations. That’s how a watch uses a quartz crystal to keep time.