The Power Read os when the quarterback reads the defensive end, and the offensive line blocks power. If the defensive end moves toward the quarterback, the quarterback will hand the ball off to the running back. The quarterback will keep the ball if the defensive end moves toward the running back.
Here is an explanation where you can see the Baltimore Ravens exploiting this concept with Lamar Jackson. I firmly believe that the Chicago Bears would be very wise to implement a few plays like that with Justin Fields.