Here are a few definitions:
An operating sytem is software that manages the computer hardware ... [it provides] an environment in which a user can execute prgrams in a convenient and efficent manner.
An operating system must fulfill two main objectives:
- Interact with the hardware components servicing all low-level programmable elements included in the hardware platform.
- Provide an execution environment to all applications that run on the computer system (the so-called user programs).
What is an operating system?
- a piece of software that turns the hardware into something useful
- layered picture: hardware, OS, applications
- Three main functions: fault isolate applications, abstract hardware, manage hardware
An operating system, as we use the term, means a collection of programs that are sufficient to use the computer to do a wide variety of jobs. A general purpose operating system, to be complete, ought to handle all the jobs that many users may want to do.The kernel is one of the programs in an operating system - the program that allocates the machine's resources to the other programs that are running. The kernel also takes care of starting and stopping other programs.
From the Linux/GNU controversy.
We defined an OS as software which:
We argued for a minimal OS which doesn’t include the filesystem.