The command stat is probably not one of the most well known commands in Linux but as with all of these video man pages , I deal with useful commands. There is lots that you can use stat for, used on its own just referencing a file it will display all the stats it can: owner, permissions, access times etc. Used with the -f option it will display information about the file-system that hosts that file.
If you are learning permissions you can display permissions both in human readable format stat -c%A and octal, stat -c%a <filename>.
It is very easy here to show the difference between the last modify date ( -c%y) for a file and the last change date(-c%z). The last modify time is when the file itself was changed and the last change time is when the inode or entry in the file-system was changed.This would be permissions or ownership etc. I think the video will be of interest.