Class is one of the important features in Object Oriented Language.It will be very confused for people who are first time to learn programing. Since I came across from JavaScript, which language does not come with "Class", yet it shares similar concept.
Generally speaking, creating Class can help us create instances much more efficiently. Methods are class' properties.
Let's see how we can create / define a class.

Second, you may want to initialize some instance variables for this class.

Besides initializing variables, you may also want to set some instance variables for defining methods.

When you are going to generate an instance of this class, you need to

That's all you need for create a class