A bootable CD that contains only an OS or an OS and application that run without being installed. Used for demonstration and evaluation as well as system recovery, the software runs intact from the CD. However, installation is often offered as an option. LiveCD functions are also stored on a DVD or USB drive (LiveDVD or LiveUSB).
For Testing and Evaluating
LiveCDs are popular for testing machine compatibility with new software. For example, Linux versions are commonly found on bootable LiveCDs and LiveUSBs. The Linux version can be evaluated without disrupting the OS already in the computer. See
LiveDistro and
virtual appliance.
Restoring a Failed Computer
LiveCDs are widely used for troubleshooting a computer that does not boot (see
bootable disk).