 So you don't understand flat and polygroup, not a problem. This just means that it will apply the action to every face that is the same color and angle as the one that you left click. So if we go to this side, you see a blue polygroup. If we left click anywhere here, every face that is both blue and facing the same angle as the one I clicked is going to be affected. And the polygroups don't have to be touching each other. If we go over here to this green side, you'll see we have a green area here and one green polygon up here. And even though they're not connected, once we pick one and left click, you'll see all of them be affected. And that is because they are both green and they are both facing the exact same angle. So hope that helps and as always, hope you have a fantastic day and I'll see you around.