What is this simulated golf TGL I am watching?!?!

Am I watching Tiger and other Pros on some golf simulator? I'm at the bar and just glanced over at these guys laying on the green staring down a putt; but then seeing them hit at a simulator..... and Tiger is there, looking 40..... WTHeck. Is this popular right now? Am I too far distanced from what is going on in PRO golf?