Abstraction: reduces complexity of task by allowing user to only deal with a simplified representations or objects Inheritance: allows classes to take on all the attributes (fields, methods, etc...) to another class (super class), making the super class's attributes usually a subset of its own Polymorphism: allows objects that extends to other objects to have different, sometimes conflicting methods to choose from (method overloading/method overriding) Encapsulation: keeps private fields private