What is 'Context' on Android?

Question

In Android programming, what exactly is a Context class and what is it used for?

I read about it on the developer site, but I am unable to understand it

Answer 1

 Context means current. Context use to do operation for current screen. ex.
  1. getApplicationContext()
  2. getContext()

Toast.makeText(getApplicationContext(), "hello", Toast.LENGTH_SHORT).show();