You can create CD and DVD images using disk utility. However, those disk images are formatted using a MAC format that will not be recognizable in Windows, and requires special drivers in linux.
Fortunately you can work around this. First open disk utility and create a DVD or CD disk image. Drag your files into this disk that will appear on your desktop. “Eject” the disk when done, and open a terminal and type this command:
hdiutil makehybrid -iso -joliet -o myCD.iso myCD.cdr
I thought mac was supposed to be easy? I wonder why this isn’t built into disk utility?