Developable Surfaces are ones with 0 gaussian curvature, they have only one direction of curvature.

Parallel Extrusion

Conic Extrusion
There are 3 primary types of developable surfaces in Rhino and most other 3D modeling software.
Faceted polysurfaces
unroll command, developable surfaces and polysurfaces can be laid flat.unroll using the dupborder and dupedge command.