Live CD
From MEPIS Documentation Wiki
The term Live CD refers to a CD or another medium (such as USB stick) that contains an operating system that can be booted without installation. This can happen because operating files are placed into temporary memory instead of being located permanently on the hard disk. It is a handy method to demo a new OS without having to install it.
MEPIS provides a LiveCD that is combined with an installer, and was the first Linux distibution to do so.

