Electronic watches are usually operated by the current from a battery (special case: in addition to this, the current is also supplied by a solar cell).
The time standard (rate) is generated by a circuit of electronic components and controlled by means of a quartz-stabilized oscillating circuit.
A further development is the radio-controlled watch, in which a time signal (atomic time) emitted by a time transmitter is received regularly and the standard time is synchronized with it.