Convert ndo to x

What is the difference between .ndo and .x?

Description: NDO is a 3D low-polygon modeling program used to create low-resolution 3D objects and scenes. It features a variety of tools and functions to help users create low-polygon models, apply textures and materials, and construct 3D scenes.; X is a DirectX Model image file used by DirectX technology which is for 3D graphics rendering in games. The file format specifies 3D object structures for meshes, textures, animations, and objects.