What exactly is edging, is it going to the PONR and then kegeling hard so only a little bit or no cum comes out and then repeating?

And how exactly is the best grip for jelqing, I've always done palm up but read it's supposed to be palm down so I did that and it feels so weird. Also I've heard you can get something called turkey neck from it how do you jelq so that doesn't happen? Medical term is penoscrotal webbing I believe.