Disk cloning software makes an exact copy (clone) of a storage medium such as a hard disk (HDD) or SSD by using software techniques to copy data from a source to a destination drive or to a disk image. For example, a bootable identical SSD clone can be made of a working HDD that boots into Mac OS.
Note: the operating system listed is the operating system (OS) the cloning software runs under. Some cloning software can be used to clone storage media with a different OS installed, either by booting a host computer into the cloner's OS (for example, with a boot "rescue" CD, DVD, or USB-connected boot medium), or by connecting the storage medium being cloned to a computer running the cloning software.