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.
This provides modular approach to programming. Classes. A class is a concept used in object oriented programming languages such as C++, PHP, and JAVA etc. Apart from holding data, a class is also used to hold functions. An object is an instant of a class. In case of variables, the type is the class whereas the variable is the object.
An function defined in a class is called a method. Methods have access to all the data contained on the instance of the object; they can access and modify anything previously set on self. Because they use self, they require an instance of the class in order to be used.