2D and 3D refer to the actual dimensions in a computer workspace. 2D is "flat", using the horizontal and vertical (X and Y) dimensions, the image has only two dimensions, and if turned to the side becomes a line. 3D adds the depth (Z) dimension. Daily, we come across various objects with different shapes and sizes like triangles, squares, circles, etc. Some of these shapes which have length, breadth and height, are called 3D or three-dimensional objects. Other objects like a sheet of paper which have length and breadth are called two-dimensional or 2D shapes. 2D shapes are drawn using X-axes and Y-axes. 3D Shapes: 3D stands for "Three Dimensional". A 3D shapes have three dimensions- Length, Breadth, and Height or Depth. In chapter 19, representing 3D in 2D students will learn Euler's formula, two-dimensional shapes, three-dimensional shapes, view of 3D shapes, etc.