What is an application programming interface?
An application programming interface (API) is a specification for how one program asks another one for information.
What is a graphical user interface?
A graphical user interface (GUI) is an easy-to-use interface that lets users click on-screen elements.
What is a command line interface?
A command line interface (CLI) allows users to interact with a program by entering commands in a terminal.
Why is API important?
APIs allow you to pull in external resources data. Developers working on large, collaborative projects can build their own APIs to design how each program in the project communicates. Building and designing a good API requires planning and experience, but learning to use an API is much simpler.
Why is GUI important?
Using a GUI is the simplest way for nontechnical users to interfact with a program. For example, a weather website would present information in a browser (a GUI) for general users, but it might also provide an API that technical users can work with to build projects which use real-time weather data.
Why is CLI important?
A CLI enables automation and scripting in a more customizable fashion than with GUIs.