[techtalk] Memory Usage

[Beverly Guillermo]

Here's my scenario -- I start my linux box and check my available
memory space with 'free' and get the following:

-------------------------------------------------------------------------
             total       used       free      shared    buffers    cached
Mem:        258104      38564     219540      12108       6872      22504
-/+ buffers/cache:       9188     248916
Swap:       128516          0     128516
-------------------------------------------------------------------------

and when start another program, then exit, and check 'free' I get.

-------------------------------------------------------------------------
             total       used       free     shared    buffers     cached
Mem:        258104      50932     207172      12888       8308      32672
-/+ buffers/cache:       9952     248152
Swap:       128516          0     128516
-------------------------------------------------------------------------

Am I reading this wrong?  Shouldn't I get back the memory I used when the
program exits/terminates?  

Is there a better program to check memory usage?  If so, what is it?

Of all the years I've used linux, I could never figure out what is going
on with memory usage.

Beverly