operating system LastModified: Sunday, October 25, 2009
The most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop -- it makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system. Operating systems can be classified as follows: multi-user : Allows two or more users to run programs at the same time. Some operating systems permit hundreds or even thousands of concurrent users. multiprocessing : Supports running a program on more than one CPU. multitasking : Allows more than one program to run concurrently. multithreading : Allows different parts of a single program to run concurrently. real time: Responds to input instantly. General-purpose operating systems, such as DOS and UNIX, are not real-time. Operating systems provide a software platform on top of which other programs, called application programs, can run. The application programs must be written to run on top of a particular operating system. Your choice of operating system, therefore, determines to a great extent the applications you can run. For PCs, the most popular operating systems are DOS, OS/2, and Windows, but others are available, such as Linux. As a user, you normally interact with the operating system through a set of commands. For example, the DOS operating system contains commands such as COPY and RENAME for copying files and changing the names of files, respectively. The commands are accepted and executed by a part of the operating system called the command processor or command line interpreter. Graphical user interfaces allow you to enter commands by pointing and clicking at objects that appear on the screen. See "What's the Top Net Operating System?" in the Did You Know...? section of Webopedia. See also "Formatting a Hard Disk Drive" in the Did You Know...? section of Webopedia.
Virtual Doctor  Using the Virtual Doctor, users can acquire help with a specific problem, download software, grab updates for their operating system or receive expert tutorials catering to their specific needs. CMX-RTX real time operating system Product feature page for the CMS-RTX real time multitasking operating system for microprocessors and microcomputers. OS News On-line magazine covering alternative operating systems and computing environments. osOpinion Daily computer and operating system news and opinion commentary. RTMX operating system information page Provides product information for the RTMX real time operating system, including features and supported CPU types. In addition, there are links to related real time computing Web sites. A Quick Reference to Microsoft Windows Vista For years, computer users heard of a mysterious new operating system from Microsoft, codenamed Longhorn. In 2005, Microsoft officially removed the Longhorn codename and announced the operating System under the official name of Windows Vista. Get Your PC Ready for Windows Vista If you plan to upgrade to Vista, there are some things you need to consider first such as which version, data backup and file transfer. Linux Today Daily updated Linux news on developers, performance issues, infrastructure, IT Management and more. Webopedia Did You Know...? All About DirectX While you may be familiar with the "Would you like to install DirectX now?" window, do you know what DirectX is, and why it is important to keep an updated version of it on your PC? Webopedia's "Did You Know...?" Section Use this Webopedia knowledge section for an in-depth overview of specific technologies and occurrences in the areas of Computer Science, The Internet, and Computer Hardware and Software.	related categories: Operating Systems OSRC Operating Systems related terms: abort application BeOS BIOS command processor DOS fatal exception error file management system flat file system kernel kernel32.dll Linux Mac OS Microsoft Windows multiprocessing multitasking multithreading multi-user MVS NTLDR open source operating system virtualization operating system-level virtualization OS/2 PXE UNIX VMS Windows 2000 Windows CE Windows XP Shopping operating system Products Compare Products,Prices and Stores Shop by Category: Software 3336 Store Offers Input Adapters 4 Model Matches