LaTex: Difference between \overline and \bar

Today I wanted to put a bar over an uppercase variable W. When I used \bar{W} it was way too small. I used \overline{W} in instead.

\bar{W}

\overline{W}

Terminal: DU to show disk usage

I saw my advisor use this command today. I can't believe I didn't know about it.

$ du

returns the disk usage of each file in the current directory.

-s returns the sum of the disk usage for all the files.

-h puts output in human readable format

example:

$ du -sh

900G