'Arguments' and Spread 

Arguments: The parameters you pass to a function 
           Javascript gives you a keyword of the same name whch contains them all

Spread is the new way of doing arguments using ...

Excecution Context is Created sets up:
    - Variable Environment: Hold us variable
    - 'this'
    - Outer Environment: for Scope Chain
    - 'arguments': Contains a list of all the values of all the parameters that you passed to a function 


function greet(firstname, lastname, language){
    console.log(firstname);
    console.log(lastname);
    console.log(language);
}

We get 'Undefined' for the console because of Hoisting