On Monday, Facebook announced that it was buying Israel's Face.com, a company that specializes in facial recognition technology. The purchase, rumored to be worth somewhere between $55 million and $60 million, is the latest photo-related acquisition for the social network, which famously purchased the photo-sharing app Instagram for $1 billion earlier this year. What is Facebook playing at? Here, a concise guide to the latest purchase:

What does Face.com's technology do?
The company's iPhone-only software instantly detects and recognizes people's faces in any photo snapped using Face.com's technology. "Thousands of developers, including Facebook itself, have built applications using Face.com's online software," says Laurie Segall at CNN, which also tries to pin down a person's gender and approximate age just from scanning their face.

Why does Facebook want Face.com?
Right now, "there's probably a ton of untagged mobile photos getting posted" on Facebook, says Alexia Tsotsis at TechCrunch. "Those tags are lost opportunities for engagement because when you get notified that you've been tagged in a photo, you probably visit Facebook immediately to check it." Potentially, the acquisition allows mobile users to upload a Facebook photo on the go and instantly receive a suggestion for who to tag with one-click approval, dramatically streamlining the process. 

Is purchasing Face.com a smart move?
Maybe, says Andrew Nusca at ZDNet. At the very least, it provides a "chance for Facebook to bring compelling technology to a wider audience." And when the $1 billion deal for Instagram closes, Facebook may latch Face.com's facial recognition technology onto its new retro-inspired photo service, or onto its perplexing new Facebook Camera app. "With Instagram and Facebook Camera on the front end and Face.com on the back, Mark Zuckerberg has the arsenal he needs to win the war for mobile photos," says Tsotsis.

Sources: CNN, New York Times, TechCrunch, ZDNet