In general usage, an interface is the point, area, or surface along which two substances or other qualitatively different things meet; it is also used metaphorically for the juncture between items. The word interface is sometimes (usually in technical disciplines) shortened to "i/f".

The verb to interface means to interconnect two or more entities at a common point or shared boundary, or to prepare either entity for that purpose.

The word interface also has the following specialized meanings:

• The user interface is the functional and sensorial attributes of a system (appliance, software, vehicle, etc.) that are relevant to its operation by users.
• In electronics and computer engineering, an interface may be
  • The physical boundary between two subsystems or devices.
  • A part or circuit in some subsystem that sends or receives signals to or from other subsystems: network interface, video interface , network card.
  • A standard specifying a set of functional characteristics, common physical interconnection characteristics, and signal characteristics for the exchange of data or signals: USB interface , SCSI interface .
• In telecommunications, a point of interconnection between user terminal equipment and commercial communications facilities.
• In software engineering, it is a specification of those properties of a software component that other components may rely upon: see interface (computer science).
• In chemistry, it is the surface between two distinct phases in a heterogeneous mixture.
• In geology, it may be a surface or anomalous layer between two distincive geological epochs or rock types.

See also

• network interface
• network card
• user interface
• Knowledge visualization