Base64

Base64 is a command that turns data into text or reverses that process, following the recommendations of RFC 3548. This is used primarily for safely transmitting data in email communications.

Provided by
Most (all?) Linux distributions incorporate this from the GNU Coreutils: and use its man page

Related Commands
These all relate to the output or processing of entire files
 * cat -- concatenate files into a single result.
 * tac -- line-reversed cat
 * rev -- character-reversed cat
 * nl -- output with line numbers
 * od -- dump in octal and other character representations.