BIG DEAL: Facebook is making its largest acquisition ever and spending $1 billion to buy the photo-sharing company Instagram.
WHAT IS IT?: Instagram lets people apply filters to photos they snap with their mobile devices and share them with friends and strangers. Some of the filters make the photos look as if they've been taken in the 1970s or on Polaroid cameras.
THE DETAILS: Facebook plans to keep Instagram running independently. That's a departure from its tendency to buy small startups and integrate the technology — or shut them down altogether just so it can hire talented engineers and developers.

