Alternating Current (AC):

Alternating current refers to the current whose direction changes periodically over time, with the average current over one cycle being zero. It is typically generated by an AC generator or produced through DC/AC inversion.

Characteristics: The waveform is a sine curve, with a variable period (frequency), and it is not easy to store. The mains electricity used in daily life is alternating current with a sine waveform.

Direct Current (DC):

Direct current is the current whose direction remains constant. It is typically generated by electrochemical processes, photovoltaic (PV) solar cells, or batteries.

Characteristics: DC has positive and negative terminals, the current direction remains unchanged, and the voltage is stable without the periodic variations (no frequency) seen in AC. It is suitable for powering electronic circuits and is easier to store.

Note: AC and DC can be converted using technical methods.

Converting AC to DC is called rectification.

Converting DC to AC is called inversion.