Functions, Context And Variable Environment

Variable Environment - Where the environment live and how they relate to each other in memory (Where is the variable?)

• Scope!!!!

function b (){
    var myVar;
}

function a () {
    var myVar = 2;
    b();
}

var myVar =1;
a();

- What is the value of myVar? 
    - Global Execution Context is executed (myVar = 1)
    - a() -> New Execution Context is created for a() - 
             Every execution context has its own execution context so myVar = 2
    - b() -> New Execution Context with its own variable environment and memory space so myVar = Undefined 
  This something to do with scope, where are we able to see the variable.
  Each variable is defined in its own execution context, because it is within a function. 
  Every time you call a function, you get a new execution context