A typical e-Home CONTROLS system consists of a core service and several clients and interfaces. These clients and interfaces are commonly known as 'components'. When a component connects to the central core service, it registers the types of devices it supports, as well as any functions, properties and events it provides. For example, the e-Home CONTROLS HDL Interface is a component and it registers device types (such as 4 channel relays, motion sensors and switches), functions (such as 'auto find') and properties (such as the TCP port it uses)