Did you look at "man ps" -- it has the answers to your questions.
VSZ: Vsize -- virtual memory size of the process
RSS: Resident set size -- amount of the processes memory space that's actually mapped to physical memory
%MEM: percentage of physical memory used by the RSS, i.e. RSS/TotalMemory
Seriously, check the man pages -- this information is documented!
Last edited by btmiller; 12-06-2009 at 12:59 PM.
Reason: I can't spell