Mac OS X Snow Leopard introduces Stacks in the Dock, which allow users to view and access files, documents, and applications directly from the Dock. Stacks can be configured to automatically display their contents in a grid or fan layout based on the number of items. Users can create their own Stacks by dragging folders onto the Dock and customize settings like sort order by right-clicking on a Stack icon in the Dock. The Dock includes pre-made Documents, Downloads, and Applications Stacks to easily access common file types.