Parallel parking is very difficult to learn while driving. When you parallel park you are trying to move your car into a space that is in front of another car or in back of it. Usually you see parallel parking on the sides of roads. These parking spaces are for shoppers usually because they are in front of a strip mall or a row of stores on a busy street.
It is hard to learn to parallel park because we are so used to parking in a regular parking space. You need a lot of practice to learn how to parallel park. One way to parallel park is to back into the space. Many people have to back into the space when they parallel park which is difficult to do.