Transmission
A transmission has some gears that change the torque more than other gears. That is why a transmission has a first gear, second gear, third gear, and sometimes more gears. There is also a reverse gear and neutral. An automatic transmission shifts between gears by itself (except reverse gear, and a parking gear). A manual transmission needs the driver to decide when to shift gears. Manual transmission is also called standard transmission. This is confusing because almost all cars in the U.S. have automatic transmission. In other words, since the late 20th century "standard" transmission has been unusual. A manual transmission usually has a clutch pedal, which the driver must press while shifting gears. An automatic transmission has a fluid coupling called a torque converter instead of a clutch. Some cars have a "clutchless" manual (semi-automatic) transmission, which has an automatic clutch (no clutch pedal), but does not shift gears by itself.