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.
(Admittedly it would make more sense for a class with a main method to be something one could obviously execute - a main method in a Student class doesn't make as much sense.) Objects don't really have methods - classes have methods, either static methods which are called without any particular context, and instance methods which are called on a particular object of that type (or a subclass).