3-D Shapes and Nets
Most 3-D shapes comprise some FACES, EDGES and VERTICES.
The FACES are the flat parts of the shape. Some FACES are curved.
The EDGES are like the 'lines' in a 3-D shape.
The VERTICES are the corners (the 'pointy' bits!).
A net is what you have when you open out a 3-D shape.
A net can be folded up to form a 3-D shape.