Hello!  I'm performing research for a new CMS.  I'm the webmaster for my county and our government has various departments each with web contributors.  Does Umbraco have built in support to limit certain users to only create pages in certain sections?

Also, does Umbraco have a media library, or is media handled on a per page/post method?  Let's say for example, Department-A needed to create a library of PDFs and members from other Departments shouldn't be allowed to upload to this library... is there a way in Umbraco to manage files this way?

Any and all input is greatly appreciated.
Thanks!
Brad