A gear shifter is a mechanical device in vehicles that allows the driver to change gears in the transmission. It is typically found in both manual and automatic cars, enabling the driver to select the appropriate gear for different driving conditions. In manual transmissions, the driver must engage the clutch while moving the gear shifter, while in automatic transmissions, the system shifts gears automatically based on speed and engine load. The gear shifter can come in various forms, including a stick, lever, or dial. In manual transmissions, it usually has a pattern indicating the gear positions, while in automatic transmissions, it often features settings like "Park," "Reverse," "Neutral," and "Drive." Proper use of the gear shifter is essential for optimal vehicle performance and fuel efficiency.