In this video, you learn about the three very different classes of warplane seen in World of Warplanes: fighters, heavy fighters, and ground attack aircraft. Fighter are good against other fighters, heavy fighters can take more of a beating than a standard fighter which makes them the aircraft of choice to take out larger target, and ground attack aircraft are great for hitting ground installations and armor columns.
Also, if you're a student of Eastern European languages, then you can use this video to practice for your next test.