Interfeys

Interfeys is a boundary or point of interaction between two or more components, systems, or layers that enables the exchange of information, energy, or influence. Interfaces define how components communicate and cooperate while keeping their internal workings separate.

Common types include user interfaces (UI) between people and machines, such as graphical user interfaces and command-line interfaces; application programming interfaces (APIs) that expose functionality between software components; and hardware interfaces, including connectors and communication protocols. Network interfaces describe how devices join a network.

Good interface design aims for clarity, stability, and minimal assumptions. An interface specifies the visible behavior, inputs and outputs, data formats, and error handling without revealing internal implementation. In software, interfaces provide contracts that enable decoupling, testing, and polymorphism, while in hardware they define electrical and signaling characteristics.

Software interfaces may be defined by interface definition languages or by language constructs (for example, interfaces or abstract base types). API documentation, versioning, and adherence to standards support compatibility. Common examples include RESTful web APIs, GraphQL interfaces, and driver or device interfaces such as USB or PCIe.

A well-designed interface is stable, discoverable, and easy to use, guiding developers and users to predictable behavior. Poor interfaces increase coupling, ambiguity, and maintenance costs. See also terminology such as user interface, API, protocol, and abstraction layer.