Photo galleries are a great feature for showcasing photos on your site in a neat and fancy way.
As you can see from the sample (go ahead, click one of the photos to see what happens), galleries consist of thumbnail photos stacked in some way on your page. Each photo is a small version of the larger and by clicking it, a larger lightbox version overlays your site. You can scroll through the images and to exit simple click outside the image or hit escape. Simple and beautiful.
This feature is not limited to photography websites. It can be used by so many different type of sites like real estate, restaurant, automobile, and much more.