Understanding how to specify UTF-8

[Will Parsons]

I want to always use Unicode/UTF-8 unless otherwise specified.  I've noticed
that I've attempted to do this in my .emacs file in two separate ways on two
separate platforms:

1)  (setq-default buffer-file-coding-system 'utf-8-unix)

2)  (set-language-environment "UTF-8")

Both seem to work, but I'm wondering if there are subtle differences between
the two that I should be aware of.

-- 
Will