the most common form of user interface used on pc's today is called a
Command-line interface Today, many end users rarely, if ever, use command-line interfaces and instead rely upon graphical user interfaces and menu-driven interactions. However, many software developers, system administrators and advanced users still rely heavily on command-line interfaces to perform tasks more efficiently, configure their machine, or access programs and program features that are not available through a graphical interface.
Usage share of operating systems Since 2013, devices running Android have been selling more than Windows, iOS and macOS devices combined. Android has therefore become the most popular operating system on smartphones, while iOS is more common on tablets. Most desktop and laptop computers still use Microsoft Windows, while virtually all supercomputers use Linux and have done for over a decade. Among server computers, there is more diversity with Linux and Windows Server most popular, and many fewer mainframe OSs.