Explanation: An interface, in computer programming, is a defined means for a system to communicate with other systems. It is a boundary between a system and its environment providing ways of providing the system inputs and receiving outputs. In Object Oriented programming, class definitions and method signatures provide interfaces. Application program interfaces (APIs) form the interface of a system to applications and often consist of collections of functions or commands in a scripting language. Interfaces may be hidden (available only to the system developer) or exposed (available to others).
Other definitions in programming such as Interface in Dictionary I.