Do you often upload many pictures and/or videos to Facebook? Say, more than five in 24 hours? If so, then you'll soon see a new option presented to you by the social network. It's called Slideshow and what it does is pretty much contained in that name.
Basically Slideshow takes your photos and videos and automatically creates mini-movies from them, complete with theme music and smooth transitions. A Slideshow is initially auto-generated, but you can then edit things in it, such as adding or removing images, or changing the 'theme' of the Slideshow. Available options for the latter include Nostalgic, Playful, Night Out, Birthday, Epic, Thankful, Tropical, Bollywood, and Amped.
Slideshow made its debut in Facebook's Moments app last August, but you'll now see it in the main Facebook app. That is, if you're using an iPhone. The global rollout (which has started today) is currently limited to devices running Apple's iOS. Hopefully Android handset owners will see this in the near future too.
Facebook probably hopes this feature will get you to upload more photos and videos, which is good for it because lately people have been sharing a lot less personal content than before - links to news articles dominate users' News Feeds nowadays.