How the user interacts with the system?
Users interact indirectly through a collection of system programs that make up the operating system interface. The interface could be: A GUI, with icons and windows, etc. A command-line interface for running processes and scripts, browsing files in directories, etc.
What is a user-friendly interface?
What is a user-friendly interface? “User-friendly” is an interface that is created for a specific group of people or without a clear target audience, but is aimed at maximum user convenience. The main goal of a user-friendly interface is to provide a perfect user experience.