What is scope?
  Refers to the current context of the code which could be either 'global' or 'local'.  When one first starts a Javascript
  code it is in the global scope. Declared variables here are defined globally.  The local scope lives inside of functions
  and each function, included nested functions, have their own local scope; however, any function defined within other
  functions will have linked scopes - inner local scopes are linked outwardly.

  Why are global variables aviod?
    Global variables can some code to be indeterminate (returns different values at times) which makes tracking down bugs
    difficult.

  What is strict mode?
    A way to opt into a restrictive variant of JavaScript which has different semantics than normal JavaScript.  It
    eliminates some sillent errors and changes them into throw errors.  It also fixes mistakes that make it difficult for
    JavaScript engines to perform optimizations, and it prohibits syntax that will be defined in the future.  The option is
    enacted by witing the command 'use strict;' at the top of the file for global control or at the top of a function for
    local control.

    What are side effects, and what is a pure function?
      A side effect is when a functions is able to reach outside of its local scope to change values in other areas of
      the code.  A function is "pure" when it is determinate (returns the same value consistently with the same set of inputs)
      and cuases no side effects in the proram overall.