What is the difference between a 2D and 3D shape?

Answer 1

A 2D shape is flat. It has length and width but no height - hence no volume. A 3D volume has length, width and height - hence also a volume.
Two dimensional shapes are flat, like drawings on paper. Three dimensional shapes can be held and picked up and turned about.

Answer 2

-1

Answer 3

A 2D shape is flat, can't be handled, has no depth and no volume. A 3D shape can be held in you hand, has depth (as well as length and breadth), volume and can hold things inside it.