free . low and high memory statistics

$free -lh
             total       used       free     shared    buffers     cached
Mem:          1.9G       1.8G        80M         0B       343M       449M
Low:          1.9G       1.8G        80M
High:           0B         0B         0B
-/+ buffers/cache:       1.0G       873M
Swap:         5.6G       348K       5.6G
$