The loop mount - see contents of iso file

Imagine you downloaded an CD "iso" image and you want to see what's inside perhaps to add a few files.

As "root" (only root can do that or an user with privileges) issue the following command:

#
# mount -o loop /home/youruser/my-iso-file.iso /mnt/DISK/
#

That is: mount -options its_a_loop_device /the_path_to_the_file /the_mount_point

In this case the mount point is under "/mnt" directory (and "/DISK" directory was created) but could be any other location you specified.