System Software: Types

There are two basic types of operating systems, single program and multi-tasking.

Single program operating system:
Allows only one program to run at a time. If you are working working on an email and want to play a song, you must shut down the email application and open up a media player. This is annoying! Some hand-held devices like tablets and smart phones still use this type of operating system.

Multi-tasking operating system:
The simplest form of operating system that allows several programs to run at the same time. The programs have to take turns with the processor. It allows the user to have email open with music playing in the background while editing a spreadsheet and a chat window open, waiting for business. Much better!!

The computer must decide how many time slices each program gets. The active (or foreground) program gets the most. Some time slices would be given to programs that are doing things but which aren't the foreground program, like downloading new email, sending a document to the printer, or synchronizing files with online storage like DropBox or Google Drive or SkyDrive. These tasks are done in the background. A smaller number of time slices would be given to programs that are open but aren't doing anything. They need a little bit of time every now and then to see if they are supposed to do something yet.

Date: 2015-01-11; view: 1404