This is just snapshot of man page to refer Field description
CPU
Processor number. The keyword all indicates that statistics are calculated as averages among all
processors.
%usr
Show the percentage of CPU utilization that occurred while executing at the user level (applica‐
tion).
%nice
Show the percentage of CPU utilization that occurred while executing at the user level with nice
priority.
%sys
Show the percentage of CPU utilization that occurred while executing at the system level (kernel).
Note that this does not include time spent servicing hardware and software interrupts.
%iowait
Show the percentage of time that the CPU or CPUs were idle during which the system had an outstand‐
ing disk I/O request.
%irq
Show the percentage of time spent by the CPU or CPUs to service hardware interrupts.
%soft
Show the percentage of time spent by the CPU or CPUs to service software interrupts.
%steal
Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervi‐
sor was servicing another virtual processor.
%guest
Show the percentage of time spent by the CPU or CPUs to run a virtual processor.
%idle
Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstand‐
ing disk I/O request.