If you take a big picture view of a computer, you get three things:
Not your typical, common-or-garden Spider, Shelob is the first super-arachnid for Reason: a 4-in/20-out audio splitter. Each channel features one stereo in and five stereo outs: a pass-through, plus four independent splits. All outputs feature an off/on toggle switch and visual feedback of channel activity, plus the ability to create a time-adjustable auto-fade for the channel switches. The 'classic' Mac OS is the original Macintosh operating system that was introduced in 1984 alongside the first Macintosh and remained in primary use on Macs until the introduction of Mac OS X in 2001. Apple released the original Macintosh on January 24, 1984; its early system software was partially based on the Lisa OS and the Xerox PARC Alto computer, which former Apple CEO Steve Jobs. Operating System: Vista/ Windows 7/8; CPU: Core 2 Quad 2.6 GHz; RAM: 3 GB; Video Card: 1024 MB DirectX-compliant, Shader 4.0-enabled video card based on nVidia GeForce GTX 460 or AMD / ATi HD 5850 or better. Hard Disk Space: 25 GB; Tom Clancy Ghost Recon Future Soldier Free Download.
You should understand what we mean by 'the physical machine', and you should certainly understand 'the user'. What's meant by 'programs running on the user's behalf' is simply that when you want to, for example, write a report, you launch a word processor program (e.g. Microsoft Word). The program you launched is performing tasks, printing files, etc, on your behalf. So what's the Operating System? On your laptops it's Windows, if you own an iPhone, it's iOS or if you have another smartphone it might be Android. On another computer it might be UNIX. The operating system is a special collection of programs. The operating system manages all the other programs running on the computer, and acts as an intermediary between those programs (or the user) and the physical machine. Neither the user nor a regular program manipulates a resource like the hard drive directly. Instead, they ask the operating system to manipulate the resource on their behalf. In this lesson we'll begin our exploration of operating systems.