timestamps:

0:00 filesystem format 1:46 yes, the GNU part of GNU/Linux matters 2:51 /bin & /sbin
3:33 /lib
4:02 /boot
4:35 /dev
5:05 /etc
5:35 /home & /root
6:44 why we have lost + found
7:27 /mnt
7:49 /opt
8:28 /proc
8:52 /run
9:26 /srv
10:03 /tmp
10:35 /sys
10:49 /usr &/var
12:22 differences across distros