This is the amount of disk space and the name of the disk currently used for virtual memory.
This is the version number of the System file your Macintosh is now using.
This is the largest chunk of memory available to open an application program. If an application requires more than this amount of memory, you cannot open the application.
This is the total amount of RAM (random access memory) available to this computer. It can include memory on chips installed in the computer, and virtual memory (space on a hard disk used as RAM).
This is the amount of RAM (random access memory) on memory chips and memory cards installed in this computer.