enumeration is a list of named constants. It is created by enum keyword.
It's not required that enum constants be in all caps, but borrowing from the Sun
code convention that constants are named in caps, it's a good idea.
With this the compiler will stop you from assigning anything to a laplop except the contant values.
Enums can be declared as their own separate class, or as a class member,
however they must not be declared within a method!
DECLARING OUTSIDE A CLASS:
DECLARING INSIDE A CLASS: