Interfaces

noun

1. The point of interconnection or contact between entities.

   "Public relations firms often serve as the interface between a company and the press."

2. A thin layer or boundary between different substances or two phases of a single substance.

   "If water and oil are mixed together, they tend to separate, and at equilibrium they are in different strata with an oil-water interface in between."

3. The point of interconnection between systems or subsystems.

   "The data is sent over the air interface to the remote system."

4. The connection between a user and a machine.

   "The options are selected via the user interface."

5. The connection between parts of software.

   "This interface is implemented by several Java classes."