What is scope? Your explanation should include the idea of global vs. local scope.
  Scope refers to where variables are defined.  A global scope is where a variable is available through the entire Javascript file wheras
  local scope would be a variable that is defined and accessable only within a certain part of the file such as a function


Why are global variables avoided?
  A global variable being available through a whole document can lead to that variable being altered in different ways throught the whole
  file making a function indeterminate (returns different values in certain areas using the same input) and will make tracking down a bug
  difficult as with the golbal scope it could be altered anywhere in the code.

Explain JavaScript's strict mode
  JavaScript strict mode is a mode you can enter at the top of your javascript file that will force global variables to return undefined
  value

What are side effects, and what is a pure function?
  Side effects are intended/unintended consequences of a function outside of the declared function itself.  A pure function is one with no
  side effects and is a determinate function (always returning the same value when passed the same input).

Explain variable hoisting in JavaScript.
  Variable hoisting refers to the way JavaScript parses a file.  Javascript will pass over the file looking for all variable declarations
  and then moves them to the top of their respective scope.