To what exactly are you referring with VMWare image? The VMDK (virtual disk)? Basically, the ISO file format can be used to burn to a CD/DVD (depending on size) and boot from it in order to use Live or install to hard disk. Or it can be loaded in a virtual CD drive on VMWare virtual machine (or other virtualization platforms for that matter), to boot and / or install to virtual hard disk. The VMWare image format can only be used by virtualization platforms, like VMWare, VirtualBox, and so on. An ISO image is more useful in that it can be used in both situations (burn or load) while a VMWare image can, as far as I know, only be used in virtualization platforms. Is that the information you're looking for?