Admin has the ability to limit permissions via 4 sets of Drop Down Menu's.

Comments permissions:
Via this menu, you're able to restrict comments being made from guests or Registered Users only.

Type of upload access:
Via this option, you can set whether you would like All users to be able to upload or only Registered Users.

Use rate feature for users:
This allows you to choose whether you would like Users to be rated.

Use rate feature for files:
Here you also have the option to set the rating feature for files, usually Compressed Files (Other Files Extension)