Even at the regional level, a first officer has the same ratings as the captain now. Some fundamental differences exist between a captain and a first officer. Mainly the captain has completed the airline's captain qualification course. They have demonstrated the maneuvers and tasks required in the airline's training program (usually AQP or N&O) from the left seat. They have also received Operating Experience (OE) while in the left seat. First officers aren't usually required to complete the tasks from the left seat. Despite the similarities in training and the same ratings, the upgrade from first officer to captain can take several weeks. Much less than initial training but there is still a training process for the upgrade.