Types of Voltages: Alternating Current (AC) Voltage: This kind of voltage is bidirectional . Periodically Alternating Current reverses the direction, hence voltage level also reverses along with the current. Alternating Current (AC) Voltage: This kind of voltage is bidirectional (reversing positive and negative over time). Periodically Alternating Current reverses the direction, hence voltage level also reverses along with the current. Direct Current (DC) Voltage: This unidirectional electric charge (current) only flows in one direction. Direct Current (DC) is produced from solar panels when sunlight is passed through the solar cells. This energy is stored in batteries for later use to illuminate the lights. see more: https://blls-lighting.com/tips-and-guides/