Here's what I've come up with:

**can affect direction and size of an effect between 2 other variables (x1 and y) but it you remove the moderator(x2) the effect between x1 and y still remains.**

moderator

moderator

A

**mediator**explains the relationship between 2 variables (x1 and y). If you remove the effects of the mediator (x2) there no longer exists a relationship between x1 and y.

Please critique my thoughts and if you have anything to add that would be helpful please assume nothing about my intellect as I really want to grasp this one.