Bootable CD / DVD is a CD / DVD that is used to load computers (OS) operating systems such as Windows XP, Windows 7, Windows 8, and Windows 10.
Unlike other data CDs / DVDs, these CDs / DVDs cannot be copied and pasted into a computer. This is because only the visible data files will be copied, and the boot image on the boot record of that CD / DVD will not be copied.
Therefore, when the data is copied back to the CD / DVD and burned, the boot image is not included and cannot be used as a bootable CD / DVD.