Video doorbells

A doorbell is a signaling device typically located near the entrance of a building. Its primary function is to alert occupants to the presence of a visitor. When a button is pressed, a signal is transmitted, typically resulting in an audible chime, bell, or buzzer sound inside the building. Early doorbells were mechanical, requiring a physical pull of a cord connected to a bell.

Modern doorbells are predominantly electric. Pressing a button completes an electrical circuit, triggering the signaling device. These systems often use a transformer to reduce standard household voltage to a safer, lower voltage for the doorbell circuit. Wireless doorbells have also become popular, utilizing a battery-powered transmitter in the button that sends a radio signal to a receiver unit inside the building. The receiver then produces the alerting sound.

In recent years, "smart" doorbells have emerged, integrating internet connectivity, high-definition cameras, and motion sensors. These devices connect to a home's Wi-Fi network and send notifications to smartphones or other electronic devices when the button is pressed or motion is detected. Users can then view a live video stream from the camera, enabling two-way audio communication with the visitor. Video footage is often recorded and stored in the cloud, providing a security feature.