Fundamentals in OOPS Concepts

Abstraction
   focusing on essential characteristics of an object not all.
Encapsulation
   which hides internal details of object.
Modularity
    dividing cohesive and loosely coupled
  
Hierarchy
    (is a)
   (part of) – Aggregation
                       Containment
Aggregation(diamond)
   Inner objects life-time is not controlled by outer object.
Containment
    Inner objects life-time is controlled by outer object.
Polymorphism ( can be Aggregation
    compile
    runtime
Namespace
    Logical naming and grouping

Inheritance:
    It is white-box reusability. Concrete class can easily override the logic in base class.

Composition:
  It is black-box resuse, when I am using the object, I get access its public property but not its private.