An inside-to-out golf swing is any swing in which the club swings to the right of the target line.
Golfers with an inside-to-out swing can push the ball out to the right, or hook the ball to the left. Poor alignment, too much shoulder or hip turn on the backswing and a downswing with too much hip slide will cause an inside-to-out swing.
To get the club swinging down on the correct path you need to set up properly, have the proper shoulder and hip turn and rotate your hips toward the target as you swing down. Get these fundamentals down and you can straighten out your game.
Finish your swing with your hips turned to face the target.
Your chest and belt buckle should be pointing toward your target at the finish. A full hip turn at your finish is the end result of proper hip turn through the swing.