What does charset in locale setting affect?

["Dan B." <danb@kempt.net>]

In a locale setting such as en_US.UTF-8 (e.g., LANG=en_US.UTF-8),
what exactly does the charset/character encoding part (UTF-8) affect?

Which common programs (e.g., getty, xterm/etc., sed/grep?) do something
different based on the charset portion of the local setting?


Thanks,
Daniel