Facebook, the social networking site has made yet another update to its website. They have rolled out the hover card feature as its latest update. With the hover card feature, you can view a summed up details about a friend or a fan page by hovering/moving the mouse over their names.
As for now, facebook displays the display picture, common friends and lets you sent message to the particular person as well using the hover card.In the future, you can always a lot more additional features added on to the hover card for sure.
Do let us know what you think about this update from facebook. 
