Installation-free Distributions (Live CDs)
A Live Distro or Live CD is a Linux distribution that can be booted from a compact disc or other removable medium (such as a DVD or USB flash drive) instead of the conventional hard drive. Some minimal distributions such as tomsrtbt can be run directly from as little as one floppy disk without needing to change the system's hard drive contents.
When the operating system is booted from a read-only device such as a CD or DVD, if user data needs to be retained between sessions, it cannot be stored on the boot device but must be written to some other media such as a USB flash drive or an installed hard drive. Temporary operating system data is usually kept solely in RAM.
The portability of installation-free distributions makes them advantageous for applications such as demonstrations, borrowing someone else's computer, rescue operations, or as installation media for a standard distribution. Many popular distributions come in both "Live" and conventional forms (the conventional form being a network or removable media image which is intended to be used for installation only). This includes SUSE, Ubuntu, Linux Mint, MEPIS, Sidux, and Fedora. Some distributions, such as Knoppix, Devil-Linux, SuperGamer, and dyne:bolic are designed primarily for Live CD, Live DVD, or USB flash drive use.
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