I don't have a ton of context for this video, but I do know that it comes from a Wiffle Ball tournament in Vermont and the field is a scaled-down Fenway Park.
I also know that at these tournaments - because I've played in one - that there are only seven innings in a game, meaning that if you look at the scoreboard in the upper left corner, this catch indeed ended the game.
But watch the umpire. He's signaling a home run. I also know from experience that it is indeed an out, but I imagine there was quite a bit of arguing before a final decision was made, especially after the umpire's initial reaction.
All that being said, you need very little context to see that this is an amazing catch, so enjoy...