Amy has been fighting cancer for the past year and a half. Unfortunately, according to the above video's description, it has become terminal. Her family doesn't know how much time they have left together, so to thank Amy for being an amazing force in their lives 50 of her closest friends and family members gathered together to gift amy with the best of their dance moves and, more importantly, the best of their love. (That is clever wordplay. "The Best of My Love" was the song they danced to.)
It's hard to watch this video without both laughing and wanting to cry because the pure joy on Amy's face is so genuine and infectious. And Amy's reaction to the 50 people who have come from 5 different states to dance for her is a testament to her motto: "While we live, let us live." I imagine the hugging that happened after the dance was over were epic.