“One of the (very many) areas in which Linux has pulled ahead of
the pack is with live, complete Linux distributions on every form
of removable media. Tiny Linuxes to full-blow kitchen sink Linuxes
boot and run from USB sticks and drives, Compact Flash cards, CDs
and DVDs; so they never need to touch the hard drive, or even have
a hard drive present. Some of them run entirely in memory. Some are
smart enough to use the swap partition on the hard drive, if one is
available. There are different ways of preserving data and
configurations, the main point being you can still save data and
configurations.”