Create Meshes (Concept)-Autodesk AutoCAD 2008 Users Guide-kxcad

You can create polygonal mesh forms. Because the faces of the mesh are planar, the mesh can only approximate curved surfaces.

You can use meshes if you need hiding, shading, and rendering capabilities that wireframe models cannot provide but do not need the physical properties that solid models provide (mass, volume, center of gravity, moments of inertia, and so on).

You can also use meshes to create geometry with unusual mesh patterns, such as a 3D topographical model of mountainous terrain.

The visual style controls how a mesh is displayed, either wireframe or shaded. (VISUALSTYLES command) You can create several types of meshes.
 3D face. 3DFACE creates a planar mesh with either three or four sides.
  • Ruled mesh. RULESURF creates a polygon mesh representing the ruled surface between two lines or curves.
  • Tabulated mesh. TABSURF creates a polygon mesh representing a general tabulated surface defined by the extrusion of a line or curve (called a path curve) in a specified direction and distance (called a direction vector). 
  • Revolved mesh. REVSURF creates a polygon mesh approximating a surface of revolution by rotating a path curve or profile (lines, circles, arcs, ellipses, elliptical arcs, polylines, or splines, closed polylines, polygons, closed splines, or donuts) about a specified axis.
  • Edge-defined mesh. EDGESURF creates a polygon mesh approximating a Coons surface patch mesh from four adjoining edges. A Coons surface patch mesh is a bicubic surface interpolated between four adjoining edges (which can be general space curves). 
  • Predefined 3D mesh. 3D creates three-dimensional polygon mesh objects in common geometric shapes, including boxes, cones, spheres, tori, wedges, and pyramids. 
  • General meshes. 3DMESH and PFACE create three-dimensional polygon mesh objects in any shape.