Bootable disk
Alternatively called a startup disk, system disk, master disk, or boot disk, a bootable disk contains special files required for the computer to boot into an operating system. If the bootable disk is removable media (e.g., floppy diskette or CD (compact disc)), it bypasses the hard drive, depending on the settings in the BIOS (basic input/output system). This diskette is used to troubleshoot the computer or allow the user to copy files when a computer is down.
A "bootable disk" refers to a floppy diskette. If you're referring to a CD (compact disc) or DVD (digital versatile disc), it may be called a "boot disc" or "restore disc."
Because "master" in this context is offensive, it's better to refer to this disk as one of the alternative terms.
What is a "no bootable disk" error?
If the computer has no bootable media, or is trying to boot from media which doesn't contain a functioning boot record, the error No bootable disk or No bootable device is displayed. For information about non-booting computers or disks, see our bootable device guide.
Boot device, Boot sequence, Floppy drive terms, Hardware terms, Rufus