Deadlift is alternate grip, right hand over left under, controlled pull with hips driving forward and back pulling hard.
High pulls starts with overhand grip and the body is going forward that bit more ready to cover the balance when coming onto toes. There are many who do them as deadlift with upright row to follow, I work to make it one movement where everthing works together.
I used to deadlift with both hands over, and once I switched to an alternate grip, the gains I made were insane. My grip suffered a bit, though, but there's stuff to fix that.