01 When to use caps
When starting to extrude with a simple polygon, always think about if caps are needed or not. A cap is a copy of the polygon that is being extruded, and which fills the hole at the end of the new extruded shape. It may seem logical to add a cap if a solid object is being made, but this isn’t always the case especially if the mesh is to needs to be subdivided later in the modelling process. Make sure that you check the attributes or properties of the tool to see how caps can be added.