In the class, modified by the private property or method in the class can only access internal, inaccessible in the derived class or external.
Protecred by the modified properties can be accessed in a derived class, but can not be accessed externally.
Usually protected modified construction constructor so that it can only access can not be accessed outside in a derived class.
More than two qualifiers are in the class will be modified when it is instantiated, and the static is present on the class itself.