Rubric Set-Up

Rubric, what is a rubric?  As I have entered into my MAT program this word is everywhere.  This word has had zero meaning in my life until now.  The curriculums are filled with them and I have heard of teachers who sometimes hate them.  They can be hard to grade with but are essential to assements.  I recently had to create a rubric for a lesson plan I put together.  I defiantly used google to get a look at what was out there and to understand what was need for my lesson.  This is my very first rubric.  I don't feel like I can take all the credit as I asked my teacher friend to look it over, so I did have a little guidance.