Hi Jey

Yes all the things which entered in the XML are important for the admin

<mosinstall> Will specify what you are going to install
<name> Will specify the template name
<files> Will specify what are the files in that template
<images> Will specify what are the images in that template
<css> Will specify what are the CSS files in that template


Actually the modules is used to display the news, menus,etc in separate container which we can dynamiclly change it

Regards
Falcon