OOP is Nothing but Object Oriented Programming.
In OOPs concept is implimented in our real life systems.
OOPs have following features
1. Object   - Instance of class
2. Class    - Blue print of Object 
3. encapsulation  - Protecting our data
4. polymorphism   - Different behaviors at diff. instances
5. abstraction    - Hidding our irrelavance data
6. inheritence    - one property of object is aquring to 
another property of object
7.Message Passing:message passing is possible from one
object to another
8.Robust and Secure: every object is strong one.         
every object is secure one with their access specifiers.