burning a multi-session cd into iso
This question has been asked may times in the passed. Although, multi-session (osx/windows) was probably not mentioned in the past. The Snow Leopard DVD (OS X 10.6) has an additional session containing the Windows Boot Camp software. Below are the instructions for creating an ISO from this type of DVD.
I did test the Snow Leopard ISO using both macOS and Windows 10. Both operating systems open the ISO to different sessions.
Create your own ISO
Use these steps to make an ISO copy of your DVD:

While your Mac is started from macOS (OS X), insert the DVD in an external optical USB drive. (You can also use an internal optical drive, if you have an older Mac with an internal optical drive that still works.)
After the media mounts in the Finder, open Disk Utility from the Utilities folder (choose Go &gt; Utilities).
Select the optical drive so it's highlighted in the Disk Utility window.
Choose File &gt; New Image, and then select your DVD or from the submenu.
Choose DVD/CD master from the Image Format menu, then choose none from the Encryption menu.
Give the new file a name, then click Save. If prompted, enter an administrator user name and password. A progress bar appears while the image file is created (it might take some time to create the image file).
After imaging is done, eject your disc. If you're using an external optical drive, disconnect it from the USB port after the disc ejects.
From the Finder, locate the disk image file you created earlier. Single click on it to select it, then press the Enter or Return key on your keyboard to rename the file. Change the disk image file extension from .cdr to .iso. When prompted, click &quot;Use .iso&quot; to verify this change.


Below is the output from diskutil list disk3. The identifier for the optical drive on my Mac is disk3.
/dev/disk3 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *7.8 GB     disk3
   1:        Apple_partition_map ⁨⁩                        30.7 KB    disk3s1
   2:         Apple_Driver_ATAPI ⁨⁩                        1.0 GB     disk3s2
   3:                  Apple_HFS ⁨Mac OS X Install DVD⁩    6.7 GB     disk3s3