Rarely used gears in automatic cars

The automatic transmission car is one of the easiest to drive yet many get confused with an otherwise obvious gear system.
Besides the more familiar gears of P (Parking), R (Reverse), N (Neutral), and D (Drive), the automatic transmission car system has two or three extra gears that many people never or rarely engage.
These include L (Low), 2 (Two) and OD (Over Drive) that have specific functions and are only engaged only when it is required.
The two gears L and 2 when engaged actually present little or no difference that is why many drivers, including yours truly had or never cared to understand their function.
The Low gear, or first gear, is a mode of an automatic vehicle that allows less fuel to be taken to the engine, thereby slowing down the engine to provide more rotation.
This is a more powerful gear that can be used downhill or uphill where you need more climbing power or require a steady and low speed.
The 2 (Two) mode can essentially be used on fairly steep hills or slippery surfaces where you need more torque. However, you should note that in this mode the car will be using more fuel since there is increased rotation and energy or revolutions per minute (PRM).
Lastly, there is the OD or Over Drive function, a smaller button on the lower end or on the side of the gear lever.
Overdrive describes the operation of an automobile cruising at sustained speed with reduced engine revolutions per minute (RPM), leading to better fuel consumption, lower noise, and lower tear and wear.
Many drivers never understand the function of this small button and it is not surprising that majority of drivers, according to informal research, never use this button or will use it out of ignorance.
Such is the simple automatic transmission gear system, which could perhaps have been informed by the need for auto car manufacturers to sway away drivers from the manual to automatic transmission cars.