What is an OS?
A computer by itself is essentially dumb bits of wire and silicon. An operating system knows how to talk to this hardware and can manage a computer’s functions, such as allocating memory, scheduling tasks, accessing disk drives, and supplying a user interface. Without an operating system, software developers would have to write programs that directly accessed hardware–essentially reinventing the wheel with every new program. With an operating system, such as Windows NT or Mac OS 8, developers can write to a common set of programming interfaces called APIs and let the operating system do the dirty work of talking to the hardware.
