Intercom systems are communication devices that allow people to talk to each other over short distances, often within a building or complex. They typically consist of a speaker, microphone, and a control unit, enabling two-way audio communication. Intercoms can be wired or wireless and are commonly used in homes, offices, and schools for security and convenience. These systems can also include video capabilities, allowing users to see who is at the door or in another room. Modern intercoms may connect to smartphones or other devices, enhancing communication and control. They are often integrated with security systems, such as CCTV cameras and access control systems.