Operating systems can be classified according to number of tasks, user interface, and number of users.
Number of task
here OS could either be;
- single program operating system
which allow processing of a single task at a time. A user must exit any other interactive application before launching another thus the name single task OS, examples of such OS is Ms Dos.
- Multitasking operating system
on the other hand it allows the live ware to run more than one program apparently at the same time. It manages this through processor scheduling where by it allocates time slice to each ready task.
user interface refers to mode of interaction between user and the computer. All developments in making operating systems are focused on making user friendly interfaces. The categories as per user interaction are
- menu driven interface
suitable for beginners since it provides the user with list of options to choose from, an example which could show the functioning of this OS is ms office word 2003.
- Command line based interface
it lets the user to type a command at command prompt; a good, simple example of how this type of operating system worked is the ‘command prompt’ application in windows 7 operating system.
- The graphical user interface
abbreviated as ‘GUI’ this OS has a rectangular work area called windows, graphical representation of commands known as icons to add/ replace the menu list options, and most commands are executed by using a pointing device.
Also read: using keyboard as a mouse alternative
This mode of execution has brought about the acronym WIMP meaning; Windows Icon Menus & Pointing device. Windows 2000 and later versions support WIMP.
Number of users
this is if the OS support more than one user (multi user) or not (single user).
- Multi-user operating system
Allow more than one user to interactively use a computer at the same time (Contarary to single user). examples are UNIX, LINUX, novel and windows 2000 server.
Also read: introduction to computers.
Having known about the categories of the operating system (OS), what would be the considerations you would put in mind before purchasing one?
Key of all is the user friendliness (interface), the type of computer in terms of make and size, hardware configuration such as memory capacity, documentation available, number of users and processors.