Welcome to Mac OS X Lion.
The Dock in Lion includes Stacks, which you can use to quickly access frequently used files. Stacks are simple to create. Just drag any folder to the right side of the Dock and it becomes a stack. Click a stack and it springs from the Dock in either a fan or a grid. To open a file in a stack, click the file once. Mac OS X Lion includes two premade stacks called Documents and Downloads. You opened this file from the Documents stack. The Documents stack is a great place to keep things like presentations, spreadsheets, and word processing files. You can drag files to the stack or save them to the stack from an application. Stacks automatically display their contents in a fan or a grid based on the number of items in the stack. You can also view the stack as a list. If you prefer one style over the other, you can set the stack to always open in that style. Stacks intelligently show the most relevant items first, or you can set the sort order so that the items you care about most always appear at the top of the stack. To customize a stack, press the Control key and click the stack’s icon. Choose the settings you want from the menu. To remove a file from a stack, just open the stack and drag the item to another location. To delete a file, move it to the Trash. In fact, when you’re done reading this document, feel free to throw it out.