(n.) A boundary across which two independent systems meet and act on or communicate with each other. In computer technology, there are several types of interfaces.
• user interface – the keyboard, mouse, menus of a computer system. The user interface allows the user to communicate with the operating system. Also see GUI.
• software interface – the languages and codes that the applications use to communicate with each other and with the hardware.
• hardware interface – the wires, plugs and sockets that hardware devices use to communicate with each other.
(v.) To connect with or interact with by means of an interface.
Source: Webopedia