try - catch - finally.  Catch most specific exceptions 
first.

Abstraction, Inheritance, Encapsulation, Polymorphism
Abstraction : Abstraction is the process of identifying 
common patterns that have systematic variations; an 
abstraction represents the common pattern and provides a 
means for specifying which variation to use.
Inheritance :OOP, a parent class can inherit its behavior 
and state to children classes
Encapsulation :Encapsulation allows an object to separate 
its interface from its implementation. The data and the 
implementation code for the object are hidden behind its 
interface.
Polymorphism:Polymorphism allows objects to be represented 
in multiple forms