An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. The operating system is a component of the system software in a computer system.Application programs usually require an operating system to function.xamples of popular modern operating systems include Android, BlackBerry, BSD, Chrome OS, iOS, Linux, OS X, QNX, Steam OS, Microsoft Windows (and variant Windows Phone), and z/OS.
The aura is an electromagnetic field that surrounds every creature that exists. A form of energy emanating from your body, your aura can tell a lot about you, from your personality to your innermost emotions and conflicts.
Auras that target lands usually augment its mana generating properties (ie: Wild Growth). Auras are unique in that they are the only type of permanent card that requires a target to be cast as a spell. In any zone other than the stack, Auras do not have a target. Because of this, you cannot cast an Aura on a creature with shroud, for example, but you can attach an Aura to such a creature if you can manage to put it onto the battlefield without casting it.