What does the shift key on a car mean?

[MatthewLee]

On a car, the shift key refers to the shift lock. For automatic transmission models equipped with this button, the gearshift cannot be moved when the engine is off. By locking the gear, it ensures no gear skipping or disengagement, enhancing driving safety. Unable to shift gears: If shifting is impossible due to various malfunctions, you can press the SHIFT-LOCK button on the gearshift console with a thin, hard object like a needle to move the gear from P to N. Shift-Lock is also a specialized device for unlocking under specific circumstances, such as when the vehicle cannot start due to a dead battery. In this case, if the vehicle is in P gear and cannot be towed, pressing the shift-lock button allows the gear lever to move to N gear, enabling the vehicle to be towed. Generally, any automatic transmission vehicle will have this feature. Switching gears: Previously, automatic transmission models lacked this function, allowing the gear to be shifted from P to R, N, or even D even when the engine was off. However, in newer models, due to the Shift-Lock feature, shifting gears when the engine is off is impossible. This helps to some extent in preventing the vehicle from sliding when stationary due to accidental gear shifts.