This is an advanced system that carries audio and visual connection live to you. This can be set up in a basic system, similar to the audio systems where it connects to a receiver, or it can be set up so you can access it anywhere you are on your smart phone.
This means you can let people in your home, once you’ve verified them on the intercom, while you’re away! You can set it up so you can let delivery drivers in your front gate, or family and friends into your front door while you’re at work or at the shops.