Polygons and Quadrilaterals… Whats the Differece?

Well we all know that these are types of shapes but… Whats the difference between them?
A polygon is a closed plane figure bounded by straight sides. Now in Kid terms that is a closed shape that has all straight side. What is a quadirlateral though… it is any four sided polygon.
Here are two charts with the shapes of each group so you can eaily see the difference.
Quadrilaterals

Polygons

Teaching the difference to students is very important but also their relationship is important as well.