Projection is the conversion of a regular top-down (or side-on) view to an isometric view. Perspectives provides you commands to create isometric projections of polygons, paths circles, arcs and ellipses. You can also add lines that lock to isometric directions and circles from top down or side on projections.
Once you’ve projected something, you can make it into a floor or extrude it to make a solid shape. Alternatively you can construct isometric symbols from top down and side on Projections.