* Recursion

* constructor functions

* classes

* when solving complex algorithms recursion comes in handy. It is not that great for smaller, less complex algorithms.

* For every recursive function, you'll need to establish what is called a `base case`. A `base case` is a condition that when triggered, will discontinue the call to your function.

* Because JavaScript is both an Object Oriented and Functional Programming language, it has some very interesting concepts built into it.

* The 'this' keyword is one of those querky concepts that tend to trip up a lot of people coming into JavaScript.

* You can think of this, as a Pointer to an object. For example, you can use the this keyword to reference an object without having to refer to that object's name.