A spreadsheet program is application software. Abstract resources are virtual resources implemented the low-level system software. These resources provide important services but have no direct physical realization. Examples of abstract resources include, Ram Disks and Virtual Memory. This is ideal for data processing and number crunching applications.
Time sharing is perferred when the system is used for interactive processes.
This ideal for application development, text processing, and other user centered uses of today's computers. The scheduler will strive to minimize the time it takes for the computer to respond to each user's commands. It will also strive to minimize the overall time that it takes for all jobs to run.