An automatic transmission is a type of vehicle transmission that automatically changes the gear ratios as the vehicle moves, allowing the driver to focus on steering and acceleration without needing to manually shift gears. This system uses a complex arrangement of gears, hydraulic systems, and sensors to determine the optimal gear for the current speed and load of the vehicle. Unlike a manual transmission, where the driver must engage the clutch and select gears, an automatic transmission simplifies driving, especially in stop-and-go traffic. It enhances comfort and convenience, making it a popular choice for many drivers.