On the off chance you'd rather not fly to Vegas OR deal with amped-up Rousey fans/haters, you'll wanna default to the PPV option: fork over $50 for the standard-def stream, or spend $10 more for HD through your cable/satellite provider (FiOS, Comcast, Dish Network, TWC, DirecTV, etc).
Why it's an important event
This should even bear explaining, but waayyyyyy back in 2015 there was a little event called UFC 193. Ronda Rousey was coming off a six-fight undefeated streak since joining the UFC, and she'd also KO'd Bethe Correia in the first 34 seconds of her last tile defense. Meanwhile, Holly Holm was a relative unknown, at least when weighed against Rousey's considerable star power, so nobody expected this to be much of a fight -- and then Holm knocked the taste out of the champ's mouth with a brutal kick to the head. It was about as shocking a moment as Anderson Silva's horrific rubber leg, and nobody was sure if Rousey would be returning to the ring.