PID

process’s process ID number

USER

process’s owner

PRI

process’s priority

NI

process’s nice value

VIRT

How much virtual memory the process is using

RES

How much physical RAM the process is using (default in Kilobytes)

SHR

How much shared memory the process is using

S

process’s current status (e.g. zombied, sleeping, running, uninterruptedly sleeping, or traced)

CPU%

The percentage of the processor time used by the process

MEM%

The percentage of physical RAM used by the process

TIME+

How much processor time the process has used

COMMAND

The command that started the process