mem

goal

monitor the memory use (RAM and swap)

units

all is in percents of total memory (or swap)

parameters

programs

it is the percentage of memory used by programs

shared

it is the percentage of shared memory used (ipc)

buffers

it is the percentage of memory used by buffer

cached

it is the percentage of cached memory used

free

it is the percentage of available memory

swap

it is the percentage of swap used

more info