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.”