The text is about how to drive a car
1) Think of your car as a bike. The back wheels rotate in one straight line no matter what and that leaves you to adjust the direction of the front wheels to wherever you want to go.
And in the following I haven't understood the meaning of "opening" wheather it is a door side of driver or space where you are parking in or both. thanks a lot!
2) In order to parallel park between two cars
a. Pull up next to the cars just far enough so that the back of your car is parallel to the side of the opening closest to you.
b. Shift your gear into Reverse gear and steer the car in the opposite direction in which the cars are parked.
c. Slowly back into the opening, using your rear and side view mirrors, and stop as soon as your car is halfway into the opening.
d. Shift your gear so that you are now in the Drive mode and steer your car back to the direction of the parked cars.