Facebook's $19bn WhatsApp deal explained in 60 seconds
20 February 2014 Last updated at 16:06 GMT
Facebook has bought messaging app WhatsApp in a deal worth $19bn (£11.4bn) in cash and shares.
In a statement announcing the deal, Facebook founder Mark Zuckerberg described the deal as "incredibly valuable".
The BBC explains the background to the deal - in 60 seconds.
Video produced by Michael Hirst