An automatic transmission is a type of vehicle transmission that automatically changes the gear ratios as the vehicle moves. This allows the driver to focus on steering and braking without needing to manually shift gears. Automatic transmissions use a complex system of hydraulics and electronics to determine the best gear for the current speed and load. These transmissions are commonly found in many modern vehicles, including cars and trucks. They provide a smoother driving experience and can improve fuel efficiency compared to manual transmissions. Popular brands like Toyota and Ford often equip their vehicles with automatic transmissions for added convenience.