See below for a better explanation.
Neutral(N)-
Use N if you need to restart a stalled engine, or if it is necessary to stop briefly with the engine idling. Shift to P position if you need to leave the car for a longer period.
Drive(D)-
Use this position for your normal driving. the transmission automatically adjust to keep the engine at the best speed for driving conditions.To help the engine warm up faster,the transmission will select ratios that allow the engine to run at higher speed when it is cold.
Second(S)-
Selecting Second shifts transmission into a lower range of ratios for better acceleration and increased engine braking.Use second when you are going down a steep hill or in stop-and- go driving.
Low(L)-
To shift to Law, press the release button on the front of the shift lever, Use L to get more power when climbing, and for max. engine braking when going down steep hills.
**For faster acceleration when in D,S or L, the transmission will automatically "Kick down" to a lower range of ratios by pushing the accelerator pedal to the floor**