A cut is the action or the move which separates two almost connected groups of stones.
Cutting is a central concept in go - you are normally well advised to keep your own groups connected but cut your opponent's apart. (Strategy: Divide and conquer)
Because of the two stones, the
stones are cut off from the living white stones on the top edge.
It is worth noting that cutting stones are often themselves separated from their group, so if you are cutting two groups to capture one of them, you must make sure that your cutting stones will not get captured first.
Author: MortenPahle