A ladder seals the fate of two groups. #SickGoTakedowns #ThatWasASickGoTakedown #weiqi #baduk

Ladders are one of the very first things you learn in Go:

https://senseis.xmp.net/?Ladder

If you want to learn the game from the very beginning, may I suggest this fine website

https://www.mirthturtle.com/go/beginner