The Army MOS 19 series is for soldiers who operate armored vehicles in ground combat. They are responsible for tank and cavalry operations on the battlefield.
Here are some MOS 19 series jobs:
19B: Army Armor
19G: Army Armor Reconnaissance Vehicle Crewman
19H: Army Armor Reconnaissance Vehicle Driver
19Z: Army Armor Senior Sergeant
19C: Army Cavalry
19D: Army Cavalry Scout
19K: Army M1 Armor Crewman
19E: Army M48-M60 Armor Crewman
When choosing an MOS, you can consider if it will lead to a good paying job after you separate from the Army.