The Fission Theory: This theory proposes that the Moon was once part of the Earth and somehow separated from the Earth early in the history of the solar system.
When you actually use that class to make a THING, this is what you make. A method is a bit of code that can be called when needed (often as part of an class, but not always) Here's an example: I write a class called Ball. In my main code, I then write a=Ball.new, b=Ball.new, c=Ball.new.
Answer. Abstract classes are classes that contain one or more abstract methods. An abstract method is a method that is declared, but contains no implementation. Abstract classes may not be instantiated, and require subclasses to provide implementations for the abstract methods. Let's look at an example of an abstract class, and an abstract method.