5. Encapsulation

• Encapsulation means concealing characteristics of an entity
  from the world that has no need for these characteristics.

• Entities can be perceived either through their

  • specification ( from outside )

  • implementation ( from inside ).

• Encapsulation should be enforced by entities themselves, rather than
  by the policies in the environment in which the entities operate...

  • ...Entities are given the priority in terms of how they want to be organized internally.