Interface #

The term interface is used in a variety of contexts:

• Graphical User interface (GUI),
• Terminal User interface (TUI),
• Command-Line Interface (CLI),
• Application Programming Interface (API),
• hardware interface,
• etc.

A programming interface is a set of commands, methods, etc. that allow interacting with a program.

Examples.

• if Alice uses git via its CLI, then she has to enter commands that git recognizes as a possible inputs,
• if Alice uses git via a GUI, then her clicks trigger such commands,
• if a program calls git, then it also has to use such commands.

Warning. A programming interface usually specifies communication in one direction only. So when two programs communicate, they may use different interfaces, one in each direction