Don't be surprised if you get flamed about this question.

I am going to assume this is a legit question, in that case, the numbers 1 through 4 then the big D are indicators of the gears being used, with one being first (lowest) and so on with D being 5th gear (highest).

1st gear is where you will start from a stop. This gear, much like a bicycles low gear, allows you to get the wheels turning from a stop and requires the engine to push hard. As you accelerate and gain momentum, you need less push to get the car moving faster and as a result move up to higher gears. When in a steady state speed and needing to get a burst of speed (to pass a car or enter an on ramp to a highway), you will need that extra push and consequently will need to go back to a lower gear.

The auto-stick when left in the fully auto mode will do this all for you. When choosing your gears, it will hold that gear until it reaches a specific speed (and RPM) then will automatically upshift if you have not done so manually to protect the engine. In turn you can use the auto-stick feature to help slow the car requiring less brake input by using the engine speed as a brake.

So to answer your basic question, no the car will not accellate faster or smoother from a stop more smoothly in a higher gear (as you said 4) than using a lower gear (1). On the other hand, if the car is already rolling, depending on the speed it is traveling, droping it to a lower gear can cause the car to slow without stepping on the brake.

Tried to explain this in the most simple of terms.