Subdiv Surfaces > Standard Mode

Standard mode is a display mode for subdivision surfaces that displays a subdivision surface in its native form.

When working with a subdivision surface in Standard mode you can do the following:

Add levels of refinement to selected regions of the subdivision surface where you need more detail in your mode.
Adding levels of refinement adds vertices to the surface by subdividing the selected region.
Switch between any existing levels of refinement.
Manipulate refined components (move, rotate, or scale) and keyframe the surface.
Switch between Standard mode and Polygon Proxy mode at any stage of modeling using the marking menu.