difference between disk image [ .dmg] and copy?

[capybara]

i have a cdr disk i wanna make copies of - its getting scratched
i dont understand the differrence between a disk image [ .dmg]
which i could make with disk utility
and
just copying the disk to desktop.

isnt it an exact copy either way, so whats the diference?

[bala_1947_chandar]

If you burn a CD with a "dmg" file, you will get a CD with that one ".dmg" file on it instead of a CD which has the contents of the dmg file.

Well, if you mount the image, then burn the mounted image, not the .dmg file, it will burn it like it's the CD, not a CD with one file on it that you can mount.