A doorbell is a device which is typically installed to or near a door. When a visitor presses a button, the bell rings inside the building, alerting the presence of the visitor.
Older doorbells were fully mechanical. Newer electrical doorbells were installed by wires and use a push-button to activate the sound. The latest doorbells have wireless connections.
Images for kids
Doorbell from 1884 in Andrássy Avenue, Budapest