WordPress MU

Sorry to disturb here with this basic question. .
My goal is to set up ONE blog with the multi-author option (multiple accounts for different blog-authors publishing on the SAME blog having me as administrator ).
Is this what WP-MU is about? or should I simply install the standard WP and the multi-authors option is already in it? or as plugin of standard WP available?

Many Thanks!
Alex

Standard WP

Wordpress stand-alone does that.
http://codex.wordpress.org/Roles_and_Capabilities

MU is for *multiple BLOGS*, like at wp.com.

many thanks, bye!