vmstat output

[phyllis at bcsaic.UUCP]

I'm examining system performance on an Ultrix 1.2 system.  The output 
from 'vmstat' includes 'active virtual pages' (avm) and 'free pages'
(fre).  Can someone explain to me how to interpret this information?  
I've seen values ranging from 313/5164 (avm/fre) to 5219/2677.
Obviously a higher avm means more memory activity; but, beyond such 
obvious interpretations, I don't know what to make of these numbers.
My appreciation in advance....

-- 
Phyllis Melvin
Boeing Advanced Technology Center
...uw-beaver!uw-june!bcsaic!phyllis