Baduk is the Korean name for it, I believe. Also known as weiqi and igo, it is the longest continuously played board game at around 2500 years old.

At its core, Go is actually quite simple. Played on a 25x25 grid, stones are played on the intersection of the lines instead of the spaces. The goal is to fence off and create territory, zones of control where you expect to capture any stone your opponent might play in that area.

Stones or chains of stones are captured when surrounded. Empty spaces (intersections) adjacent to a stone or chains of stones are referred to as liberties. Once all liberties are occupied the stone(s) are captured, removed from the board, and held by the captor. A single stone has 4 intersections connected to it, so 4 liberties. 2 connected stones have 6 liberties and so on…much easier to grok that with a visual aid or a better writer than me.

If a player does not see an advantage to making any more moves they can pass. The game is concluded when both players pass. Scoring is done by each player using their captured stones to occupy their opponent’s territory and then counting what remains.

TLDR this cartoon probably does better than me at explaining it: https://www.britgo.org/cartoons/index.html