According to Wikipedia:
An ISO image is an archive file (also known as a disk image) of an optical disc in a format defined by the International Organization for Standardization (ISO). This format is supported by many software vendors. ISO image files typically have a file extension of .ISO but Mac OS X ISO images often have the extension .CDR. The name ISO is taken from the ISO 9660 file system used with CD-ROM media, but an ISO image can also contain UDF file system because UDF is backward-compatible with ISO 9660.
And if you have one of those images, you can use it under Linux in two ways.
1. Burning an ISO image
http://iso.snoekonline.com/iso.htm
2. Mount the image itself to use if from the disk.
Here we will see how to do the second one.
Create the mount point
sudo mkdir /mnt/iso_image
Mount the ISO image in the mounting point
sudo mount iso_image.iso /mnt/iso_image/ -t iso9660 -o ro,loop=/dev/loop0
or
sudo mount -o loop iso_image.iso /mnt/iso_image
It is good to define it as read only ro as that is the way CDs work
