A crystal oscillator will create an electrical signal with a given frequency.
This frequency is commonly used to keep track of time.
Quartz crystal is mainly used in radio-frequency (RF) oscillators.
Quartz crystal is the most common type of piezoelectric resonator, in oscillator circuits, we are using them so it became known as crystal oscillators.
Crystal oscillators must be designed to provide a load capacitance.
Usually, quartz crystal oscillators are highly stable, consist of good quality factor(Q), they are small in size, and are economically related.
Hence, quartz crystal oscillator circuits are more superior compared to other resonators like LC circuits, tuning forks.
Generally in Microprocessors and Micro controllers we are using an 8MHz crystal oscillator.
