Htop is a free process viewer for Linux.
Below is the Column descriptions of htop:
PID: A process’s process ID number.
USER: The process’s owner.
PR: The process’s priority. The lower the number, the higher the priority.
NI: The nice value of the process, which affects its priority.
VIRT: How much virtual memory the process is using.
RES: How much physical RAM the process is using, measured in kilobytes.
SHR: How much shared memory the process is using.
S: The current status of the process (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 name of the command that started the process.
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