The outside hook is a great move to regain possession of the ball with the outside of your foot after the ball is about to run away from you, or after you decide that you want to change direction after play and refocus on a different part or area of the field.
The outside refers to the outside of the foot meaning that you reach out the ball and turn your body around the ball while dribbling, to then go back into the space you originally came from or move the ball back in the direction where you wanted to go in the first place.
So after you do the inside hook, you're ready to get in position, it's up to you what you want to do next but the good thing is that while doing the inside hook, you shield the ball with the back of your body towards the defender.
So you turn around, you cut the ball with outside of the foot. Like the foot is positioned like a hook, so you really have the outside of the foot placed beyond the ball, behind the ball to stop the ball, slow it down, and then get your body behind the ball to shield it towards the defender.
It's an advantage you have over the inside hook, you standing, you shielding the ball towards the defender and the ball is totally in a safe place.
That's the basic idea of the outside hook.