time command - what intervals do user and sys parameters measure?

Question

I did a time on my script and this is what I got:

$ time <myscript>

real    7m5.458s
user    0m7.444s
sys     0m3.748s
$

which means that it ran for 7 minutes and 5.458 seconds.

What do the user and sys times tell me?

Answer 1

The real time is the wall clock time. The user time is the amount of time spent executing the code while not waiting for resources (I/O, network, etc.). The sys time is the time spent by the kernel on behalf of the program, e.g., executing system calls.

Answer 2

It's the amount of time actually executing code, as opposed to waiting on I/O or etc., in the program itself and in the kernel respectively.