Apple TV - Can I airplay a video through my mac, but still use it?

[Sonicrobby]

Essentially, I would like to display a live feed video from my Mac (running in the background) onto a TV through an Apple TV, but still be able to use my Mac for full screen games, daily usage, maybe even music. Is this possible? I don't really know exactly how AirPlay works, and I would like to learn exactly how it works so I can decide if I want to purchase one.