BuddyPress.org

In the readme it says to use:

include_once( '/homepages/8/d149961498/htdocs/codeismusic/wp-blog-header.php' );

Is that different from:

include_once( 'http://mydomain.com/wp-blog-header.php' ); ?

Should I leave out http://mydomain.com?

Appreciate the help, just not sure what I should change or look into…