iMac (21.5 inch, Late 2012) as a monitor
I would like to use my iMac (21.5 inch, Late 2012) as a monitor for my MacBook Air (13-inch, Early 2015). My MacBook Air would be doing all the "work," and I would just use the screen of the iMac for a bigger view of things. Is this possible? And what cable(s) would I need to make it happen? Any help is appreciated. Thanks!
iMac Line (2012 and Later)