Creating ISO files of CDs or other disks you own is a convenient way to backup, archive or (if legal) share them. And it's actually quite easy to do. Most CD/DVD burning software includes the ability to rip or create an iso image.
With this ISO image you can : Distribution of software

Mount "virtual drives" which emulate physical CDs or DVDs, such as Virtual Computers. Better performance is achieved by running an ISO image since hard drive I/O is many times faster than CD/DVD drive I/O.

To use software titles that are written in such a way that they require a physical disk to be present in order to run. Games are commonly in this category. For backup, such as PSP backups.

Professional DVD Copy for Mac in particular, is perhaps one of the easiest tools to use for this purpose.

This is a tutorial on how to use DVD Copy (to ISO) Tool to create ISO image from DVD on Mac.
Just follow steps below to finish ISO creating.

Tools you need:
1. Mac computer with at least one writable DVD drive.
2. Free Download DVD Copy Program here: Wondershare DVD Copy Pro for Mac- Copy D9 and D5 on Mac Snow Leopard

Step 1. Launch the DVD Copy program.
Step 2. Insert your DVD Disc.
Step 3. Choose "ISO" to copy DVD to ISO on Mac.

Step 4. Type in the DVD name and choose the location where you want to save.
Step 5. Start copying DVD to ISO on Mac and just wait for the burning finished.

Now you have finished creating an ISO File to your Mac, then you can enjoy watching your movie on your Mac or sharing with others.

Tips: You can review the ISO image by using the Finder to mount the .iso image (double click) and DVD Player to play the DVD by specifying the location of the VIDEO_TS folder in the mounted image.