A Direct Digital Control (DDC) system is a type of computerized control system that is used to control and monitor the environment of a building. It is an automated system that is used to control and monitor the heating, ventilation, and air conditioning (HVAC) systems of a building. It is a system that is used to regulate the temperature, humidity, and air quality of a building. It is also used to control the lighting, security, and other systems within a building. DDC systems are designed to be energy efficient and cost effective. They are able to monitor and control the environment of a building in real time, allowing for a more efficient and comfortable environment. The system is also able to detect and respond to changes in the environment, such as changes in temperature or humidity, and can adjust the settings accordingly. DDC systems are becoming increasingly popular in commercial and residential buildings, as they are an effective way to save energy and money.