For the 2019 model year Ram introduced a new 1500 series body style truck but they also continued to produce the previous year's body style for the next few years. The body style that was released in 2009 is called a Classic Body Style starting in 2019 to differentiate it from the new body style trucks. There were not only body styling changes made in 2019 but also suspension changes that mean you need to know which year your truck is in order to pick the lift kit that will fit your truck.
Below are a couple of pictures to help you tell if your Ram is a Classic or a New Body Style