Operating Systems and their Purpose

 An operating system (OS) is the most important program that runs on a computer. An operating system is the framework that allows you to communicate with computer hardware in an interactive way. Without this, you would not be able to tell the computer to do anything and it would have any instructions to follow. Operating systems perform basic tasks such as recognising input from a keyboard or keeping track of files on a disk. For large systems, the operating system has even greater responsibilities and powers 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 the following:

Ø  Multi-user:  This allows two or more users to be able to run programs at the same time. Some operating systems allow hundreds of user’s access to run programs at one time.

Ø  Multiprocessing: This supports the running of a program on more than one CPU.

Ø  Multitasking: This allows more than one program to run currently.

Ø  Multithreading: allows different parts of a single program to run concurrently.

Ø  Real time: Responds to input instantly. Some operating systems such as DOS and UNIX are not real time.

Most operating systems include: user interface, job management, task management, data management and security.

Operating System Types

GUI – Is Short for Graphical User Interface. GUI Operating systems contain graphics and icons. They are commonly navigated by using a computer mouse. Some examples of GUI examples include System 7.x, Windows 98 and Windows CE.

Multi-user – a multi-user operating system allows for multiple users to use the same computer at the same time and also at different times. This includes Linux, Unix and Windows 2000.

Multitasking – An operating system that is capable of allowing multiple software processes to run at the same time or doing more than one thing at any one time. Unix and Windows 2000 are examples of this.

Multithreading – Operating systems that allow different parts of software program to run concurrently. Operating systems that would fall into this category are Linux, UNIX and Windows 2000.