Mechanical Doorbell Chime is an analog doorbell chime with two pistons that strike metallic keys in order to make the "Ding Dong" sound. For example it may look something like this:
Digital Doorbell Chimes are a speaker that replicates the "Ding Dong" sound of a doorbell ring and may have various tunes. For example it may look something like this:
If you have a digital door chime you will require an adapter for the doorbell camera, please contact Customer Support.