ISO files are disc images, complete images of a CD or DVD all in one file. This file can then be “mounted” and made available as a virtual CD or DVD, allowing you to convert physical discs to virtual ones.
This is useful if you want to use old game or software discs on a modern computer that doesn’t have a disc drive. Note that some DRM copy protection schemes won’t work with ISO files unless you jump through additional hoops.
Windows doesn’t have an in-built way to easily create ISO files, although Windows 8, 8.1, and 10 can all natively mount ISO files without any additional software.
For you to create an ISO file from your own physical disc, you’ll need to get a third-party program. There are so many tools for this and many of them are packed with viruses. Beware!
InfraRecorder would give you a nice job and is free, open-source software that doesn’t come with junkware. Insert a disc, click the “Read Disc” button, and select a source drive to read from and destination ISO file to create.
And, as usual when downloading Windows freeware, Ninite is a safe place to get a variety of other tools for doing this, such as ImgBurn and CDBurnerXP. Some of these programs like ImgBurn comes with junkware in their installers if you get them from elsewhere.
To do this on Linux, you will need to do it from the terminal or with a disc-burning utility your Linux distribution may include. For example, Ubuntu uses the Brasero disc-burning utility. Open the Brasero Disc Burner, click “Disc Copy,” and you can choose to copy an inserted disc to an “Image File.” Other Linux distributions and desktops may include other, similar tools. Look for a CD/DVD-related utility and it should have an option to copy a disc to an ISO disc image file.
To creahte a ISO file from the terminal is as simple as running the below command;
sudo dd if=/dev/cdrom of=/home/username/image.iso
Replace “/dev/cdrom” with the path to your CD drive — for example, it may be “/dev/dvd” instead — and “/home/username/cd.iso” with the path to the ISO file you want to create.
Resulting disc images can be mounted with the “mount” command in a terminal or with graphical tools that basically just provide a prettier interface over the mount command.
Mac OS X
To get this done on Mac, you can use Disk Utility. To open it, press Command+Space to open the Spotlight search box, type “Disk Utility”, and press Enter.
Insert a disc, click the File menu, and point to New > Disc Image from [Device]. Select “DVD/CD master” as the format and leave encryption disabled. Mac OS X will create a .cdr file from the disc. On a Mac, this is practically just as good as an ISO file. You can “mount” it from within the Disk Utility application by clicking File > Open Disk Image.