ISO file is known for archive file of optical disc like CD/DVD . ISO name has been taken from ISO 9660.
The .iso file extention is mostly used for disc images.

In Linux you can also create .iso image of directory.The method will help to take archive of desired directory in filesystem. It has one more advantage, after creating .iso image of directory you can write the image in CD or DVD. Or You can use mount -o loop command to mount the iso file in some other directory.

Command Format :

mkisofs -o Give-filename.iso /path/of/directory

See the below given example in which we have created the iso file of directory by using mkisofs command.

linux@tuxworld:/home/sharad/Desktop$ sudo mkisofs -o backup.iso study/
[sudo] password for linux:
I: -input-charset not specified, using utf-8 (detected in locale settings)
8.31% done, estimate finish Wed Jul 10 13:32:17 2013
16.62% done, estimate finish Wed Jul 10 13:32:11 2013
24.91% done, estimate finish Wed Jul 10 13:32:09 2013
33.23% done, estimate finish Wed Jul 10 13:32:08 2013
41.53% done, estimate finish Wed Jul 10 13:32:07 2013
49.83% done, estimate finish Wed Jul 10 13:32:07 2013
58.15% done, estimate finish Wed Jul 10 13:32:08 2013
66.43% done, estimate finish Wed Jul 10 13:32:08 2013
74.75% done, estimate finish Wed Jul 10 13:32:07 2013
83.05% done, estimate finish Wed Jul 10 13:32:07 2013
91.35% done, estimate finish Wed Jul 10 13:32:07 2013
99.65% done, estimate finish Wed Jul 10 13:32:07 2013
Total translation table size: 0
Total rockridge attributes bytes: 0
Total directory bytes: 3004
Path table size(bytes): 26
Max brk space used 0
60214 extents written (117 MB)
linux@tuxworld:/home/sharad/Desktop$
linux@tuxworld:/home/sharad/Desktop$ ls -l backup.iso
-rw-r–r– 1 root root 123318272 Jul 10 13:32 backup.iso
linux@tuxworld:/home/sharad/Desktop$ date
Wed Jul 10 13:32:32 IST 2013
linux@tuxworld:/home/sharad/Desktop$