OPERATING SYSTEM CONCEPTS 231
us, the results of mouse clicks and key presses which are input devices are seen on
the video monitor which is an output device. is is the case when the user interface is
a GUI, that is, a Graphical User Interface, as we have in Windows type OSes. ere is
another user interface, that is, the command line interface (CLI) which is the interface
for MS-DOS and sometimes used for Linux and Unix. In a CLI, we type commands for
operations we need to perform. is may seem to be cumbersome, but has its plus points
once the commands are mastered.
7.6.4 | Application Programming Interface (API)
An API is a set of functions, routines or protocols to simplify the process of building
software applications. When a developer ...