There are several versions of Adobe Photoshop on the market, including Photoshop Extended CS4, Photoshop Lightroom 2, and Photoshop Elements 8.
Photoshop Lightroom 2 is designed for users, who shoot their own photos.
Unlike Adobe Photoshop CS 5, which focuses on editing individual images, Adobe Photoshop Lightroom 3 is aimed toward photographers who work with large collections of photographs.
Some of Lightroom's advantages are its compatibility with both Mac OS X and Windows, its nondestructive editing capabilities, its fast performance, its integration with Adobe Photoshop CS5, and its support for editing presets.
Although it doesn't cost as much as Photoshop, Lightroom is still more expensive than other photo image editing programs out there.