Libraries is a new Windows 7 feature that allows you to easily organize content from various storage devices on your local computer and network, including removable media, without actually moving the files. A library is a virtual folder that presents content from different locations within the same view. You can search a library, and you can filter the content using criteria such as filename, file type, or date modified.
When Windows 7 is installed, each user has four default libraries: Documents, Music, Pictures, and Videos. To access a library, open Windows Explorer and click Libraries in the left column. To add a file or folder to a library, right-click it, select Include in library,and then choose which library to add the item. The file or folder is available when you open that library.
To create a new library, open a folder and select Libraries > New library.
To customize a library, right-click the library and click Properties. The Properties window allows you to add folders to the library by clicking Include a folder. You can also change the icon for the library and customize how items are arranged.