The ones that are not a part of the operating system and their absence may not cause a problem. Usually the user has installed them but the ones installed by PC manufacturers can be called user application too.
It is an application's user interface - how the user controls the use of the application.
Yes! Ofcourse.
In which situation running applications of a user account remain active? *
modules
User mode. Seriously, that's what it's called.
Api
Software that allows your computer to interact with user applications and hardware is called the operating system (OS). The OS manages hardware resources, provides a user interface, and enables the execution of applications. Examples of operating systems include Windows, macOS, and Linux.
Apple applications are intended for a user that wants to accomplish a number oif tasks fast. They are meant for people who look for entertainment, news, education, and easy communication.
user roles with specific permissions
programming language software
programming language paradigm
an operating system is the intermediate between computer applications and user.