very easy, the system software is the base, like windows, mac os lion, linux, the application software run on the system software, like windows live messenger, coda, or gimp, sorry my bad english i dont know speak it, bye.
Actually, a system software is any computer software which manages and controls computer hardware so that application software can perform a task. Operating systems, such as Microsoft Windows, Mac OS...
Systems software refers to the computer programs that allow the machine to operate correctly.
Applications software are the programs that you run to do your wordprocessing, game-playing, emails,...
Typically System Software invokes (or starts, or executes) the Application Software. The Application Software then makes calls into the System Software to obtain resources (e.g. more memory), and...