There are several item types considered "Container items":
Each of these has a link next to the container title that will take you to a page displaying the container details:
The Details View allows access to widgets for any of these item types. Folders can be configured, for instance, to have attachments. These attachments can only be accessed by switching to the Details View.
Other features that can be accessed from Details View:
|•||Subscribing to the container item.|
|•||Any widget such as Synchronized items or Relationship rules.|
|•||Edit button for name and description of the container itself.|