An ISO image file is a snapshot of the data and layout of a CD or DVD, saved in ISO-9660 format.
ISO image files are widely used for storing CD content. ISO is a common CD image format for DOS, Windows (Joliet ISO extension), Linux (RockRidge ISO extension), and other operating systems.
The most common use of an image file is to write it to a blank CD-R or DVD-R, resulting in an identical copy of the original disc including file name and volume label information. ISO image files may also be opened and their contents copied to a local folder, much like ZIP files. ISO files may also be virtually mounted and accessed as a device.
Most CD-R writing software includes a feature to create a CD from an image file. You cannot copy the .ISO file to the CD-R/CD-RW, you need to have or to install a third party utility that "burns an image to disk", for example:
The applications will have an option called "Burn image to disk" which will allow you to select the ISO file and commence the burning process. You may also be able to double click on the ISO file to start recording.