OS X Lion: What is the Sidebar?
All Finder windows have a sidebar that displays icons for things you frequently use, including disks, servers, and folders.
The sidebar is divided into these four sections:
This section has icons for folders you use most frequently. Your home folder, with a house icon, appears here. A few of the folders inside your home folder are also listed here, including All My Files and Applications.
You can add folders to the Places section by dragging them there. Keeping your favorite folders here is a convenient way to quickly access them.
This section has icons for shared computers and servers on your local network, including AirPort disks and Time Capsules. If there are too many shared computers and servers to fit in the sidebar, click All. You may need a user name and password to access a shared device.
If you don’t see a Shared section, it means Mac OS X doesn’t detect any other servers on your local network, or you’ve deselected Shared items in Finder preferences.
This section has icons representing your computer, your internal disk and any other disks attached to your computer, any CD or DVD discs in your optical drive (or an optical drive available to your computer), and your iDisk, if you have one. You can rearrange the icons in this section, or remove them altogether if you like.
You can reorganize the sidebar to fit your own needs. For more information, see: