This is a lid that screws into the keg with quick connect post for the liquid connection and a bulb injector (like a cream whipper) to inject Pure Nitrogen Bulbs or Cream Charger (N20) Bulbs. There is also a 70 psi pressure release valve.
Chrome and Brass Tap
Basic tap on a plastic quick connect. A solid option for most circumstances. Can be removed at any point.
Premium Stout Style Tap
These taps are specifically designed for stout or nitro coffee etc. They are harder to accidently bump on and can pour a burst of foam by pushing back on the handle.