Private and Public
In other programming languages there is the notion of private and public classes and methods.
A private class is something that can only be accessed from within a certain file or directory and a private method is something that can only be called from within the class.
A public class or method is something that can be accessed anywhere.
However, In python this does not exist. Every class and method in python is public and there is no way to change that. We can only simulate creating private classes and methods by using certain notation and conventions.
To declare something as private we use one underscore before the name.
The reason we declare things as private is to tell the programmer not to use them. It is somewhat a warning to the programmer saying that this class or method is private and that they shouldn't mess with it.
Now that you are done learning about classes and objects I recommend you to move onto intermediate python programming.