There are two different classes of 2D elements. The basic 2D element is the normal finite elements used for structural applications included in-plane and/or out-of-plane behaviour. The load panel element is a non-structural element used to apply load to beam elements.
The Refine quad elements dialog box is used to refine Quad4 and Quad8 elements at a specified corner by splitting the elements in the following manner:
The Split quad elements dialog box is used to split Quad4 and Quad8 elements into a number of elements of the same type maintaining element releases and offsets as originally defined. The split is specified in terms of an equal number of elements along edges 1 and 3 and an equal number along edges 2 and 4.