Why did Apple TV AirPlay Display suddenly appear on my computer?

I keep up fairly well with the upgrades on my 2014 Macbook Air, and was just recently perusing for software updates. When I saw the new icon on my home bar labeled AirPlay Display, I kind of freaked out, because I never authorized downloading this, and I don't even know what it is. Further to the point, as I don't own a TV, I have no use for this application and I don't want it. Is there a way to disable it from my computer? Ir at least verify that this isn't some sort of hack or something?