Yes – that’s it in a nutshell. If you want to give them different names so that you can identify the various boxes in the Admin area, you can use something like:
if (function_exists('register_sidebar')) {
register_sidebar(array(
'name'=> 'Box 1',
'id' => 'b1',
'before_widget' => '<div id="%1$s" class="widget_wrapper"><div class="widget_box">',
'after_widget' => '</div></div>',
));
register_sidebar(array(
'name'=> 'Box 2',
'id' => 'b2',
'before_widget' => '<div id="%1$s" class="widget_wrapper"><div class="widget_box">',
'after_widget' => '</div></div>',
));
}