In a standard automatic transmission, the gears are basically gears -- interlocking, toothed wheels that enable transmit and modify rotary motion and torque. A combination of planetary gears makes all of different gear ratios the transmission can create, commonly 4 ahead gears and 1 reverse gear. Positively Infinitely Variable (PIV) https://emilianojlidy.blogs100.com/34398643/cvt-toyota-fundamentals-explained