Object Oriented Programming:
Refers to a programming methodology based on objects, instead of just functions and procedures. These objects are organized into classes, which allow individual objects to be grouped together.

Class:
 A category of objects. The class defines all the common properties of the different objects that belong to it.

Object:
 A self-contained entity that consists of both data and procedures to manipulate the data.

Composition & Aggregation:
A relationship between two objects as composition when one object owns other while an aggregation when one object uses another object.

Inheritance:
 A feature that represents the "is a" relationship between different classes.

Polymorphism:
 A programming language's ability to process objects differently depending on their data type or class.

General Programming:
Programming languages designed to be used for writing software in the widest variety of application.

Interface:
The languages and codes that the applications use to communicate with each other and with the hardware.

Abstraction:
 The process of picking out (abstracting) common features of objects and procedures.

Primitive:
 A variable defined with a primitive data type: byte, short, int, long, float, double, char, or boolean.

Encapsulation:
 The process of combining elements to create a new entity. A procedure is a type of encapsulation because it combines a series of computer instructions.

Constructor:
 A special type of instance method that creates a new object. In Java, constructors have the same name as their class and have no return value in their declaration.
Overriding:
 is a feature that allows a subclass or child class to provide a specific implementation of a method that is already provided by one of its super-classes or parent classes.

Overloading:
different methods to have the same name, but different signatures where the signature can differ by the number of input parameters or type of input parameters or both.

immutable:
 is an object whose state cannot be modified after it is created.