The Library is the default module for Lightroom. The Library module functions like a giant light table for viewing all the photos in your catalog, and in addition gives you powerful tools to rate, sort, compare, and organize your images. It is also the central hub for all of Lightroom's modules.
Locate the Parts of the Library Module
Change the Library Views
Using a Second Window
Adjust the Lights
Change the Display of the Side Panel Sections
Change Your Library View Options
Customize the Library Toolbar
Rename a Group of Photos
Tag Your Photos for Easier Sorting
Filter Your Photos
Organize Your Photos with Folders ...