An intercom, also known as a telephone entry system, provides audio and sometimes video communication between two parties. One person is typically on the secured side, while the other person is calling from the non-secured side outside requesting access to be "buzzed in." The person requesting access usually does not have a key/card/fob to have permanent or temporary access through this door or gate. The person requesting access typically either presses a button on the intercom or scrolls through a menu of names and dials a code to ring the tenant's phone. The tenant typically receives calls on either a stationary indoor monitor and/or a mobile app. At that point, the tenant can grant access upon seeing the video and/or having a conversation with the audio.
The most common