Buzzers are divided into active buzzers and passive buzzers. The "source" here does not refer to the power supply, but the oscillation source. Active buzzers have oscillation sources, while passive buzzers do not. The differences between them also include: different working principles, different appearances, different prices, different test sounds and multimeter resistance measurements, different requirements for input signals, different DC voltage tests, and different applicable scenarios. Next, ATO Automation Store will explain in detail for you.