When you use or to create a 3D view of your drawing, a wireframe is displayed in the current viewport. All lines are present, including those hidden by other objects. HIDE eliminates the hidden lines from the screen.
HIDE considers the following to be opaque surfaces that hide objects: circles, text, regions, wide polyline segments, the extruded edges of objects with nonzero thickness, 2D solids, and (when working with AutoCAD drawings) 3D solids, traces, 3D faces, and polygon meshes.
If they are extruded, circles, solids, traces, and wide polyline segments are treated as solid objects with top and bottom faces. You cannot use HIDE on objects whose layers have been frozen; however, you can use HIDE on objects whose layers have been turned off.
If the HIDETEXT system variable is off, HIDE ignores text objects when producing the hidden view. Text objects are always displayed regardless of whether they are obscured by other objects, and objects obscured by text objects are unaffected.