InterfaceAn interface, in the most general sense, links or binds things, beings, spaces, or phases. In the world of computers, an interface can provide a link between hardware components. Examples of interface links include a parallel interface between CPU and print, software (both system and application programs), and the interface between a user and a computer.
The term interface refers to many components of the Internet, from an API (application program or programming interface), GUI (graphical user interface), to neural interface. Every computer user knows what a parallel or serial interface is. It connects the computer to peripheral hardware such as a printer or a serial mouse (in the case of a PC). But interfaces don't provide only links between hardware. Software can also be linked to other software. An example of this is the exchange of information between programs. An API is such an interface; it links an application program to the operating system. Operating systems are often written in lower-level languages without consideration for application programs, which are created in higher level or compiled languages. An API is basically a translator and makes the operating system understand what kind of services the application program wants to access.
Another type of interface is the user interface, which can "connect" user and computer in both a figurative and a literal sense. An often used analogy for a user interface is the steering wheel and the pedals of a car, which enable the driver to control of a complex machine. When applying the concept of a user interface to computers, we have to distinguish between hardware and software interfaces. Input devices such as the mouse, keyboard, and microphone, or output devices such as a speakerphone and monitor are examples of hardware interfaces; graphical user interfaces (GUI) are examples of software interfaces. Windows is an example of a graphical user interface, as it links the user to DOS. MS-DOS is a Character-Oriented or Command Line User Interface; the user has to type in the commands and filenames, rather than activating them by mouse click.
Commercial and public research is currently being done to develop and define new GUIs in order to improve human-computer interaction and general usability of computers. Hypertext and multimedia are results of this research. A literal connection between computer and human user is a subject of neuroscientific research. A direct, bi-directional interface between remaining peripheral nerves in limb stumps and external hardware could help amputees control robotic limb prostheses (see URL reference number 3).