Here are some common things to remember about these components.
 Multiple polygons can share a single vertex on their outer edge.
 Multiple polygons can also share the same border edges, but never allow more than two polys to share a single edge at once. Visual errors will result.
 Multiple polygons cannot overlap and share one faces.
 Even though most programs will display polgyons with four sides, if not more, these are simply triangles with one edge hidden. Combining triangluar polygons to display quadrangles is a workflow consideration. It also helps with smoothing as we will later see.

Even though we refer to 4 sided polygons as "Quads", they are not necessarily "quadrangles" in the geometric sense (a flat plane). Remember we are talking about 3Dimensional spaces. Polygons with more than 3 points can possibly "bend" along their hidden edges.