What is the purpose or intention of the "Live CD/DVD" checkbox in a VirtualBox VM's Machine Settings Storage screen?

Question

Instructions for installing operating systems inside a VirtualBox virtual machine sometimes advise that the user ensures that the "Live CD/DVD" checkbox is checked. Other instructions don't mention this checkbox at all.

What is the purpose of this checkbox? Does its setting have any functional difference in the operation of a VirtualBox VM?

I am able to boot and install live CDs/DVDs regardless of this checkbox's setting, so I'm confused about why it's even there. I could not find a clear reference to this setting in the VirtualBox User Manual either (did I miss it?), leaving me further perplexed.

Here is a screenshot of the specific item I'm referencing:

Answer 1

Normally, when you eject a CD from the guest OS (e.g. right-click -> eject in File Explorer), it also removes the ISO from the drive (in VM settings page) and it becomes an empty CD drive.

With the "Live CD/DVD" box checked, the ISO is not removed when you eject the disk using the guest OS file explorer and it remains attached to the drive. So for example, if you were to eject the CD before rebooting, you'd still reboot to the Live CD. (without this option, it'd boot to an empty CD drive)

Answer 2

At first I was also unable to find an answer, but the mouseover (in my version) tells me:

Live CD/DVD

When checked, the virtual disk will not be removed when the guest system ejects it.