Most HTML 4.0 elements permitted within the BODY are classified as either block-level elements or inline elements. Block-level elements typically contain inline elements and other block-level elements. When rendered visually, block-level elements usually begin on a new line.
The following are defined as block-level elements in HTML 4.0:
The following elements may be used as either block-level elements or inline elements. If used as inline elements (e.g., within another inline element or a P), these elements should not contain any block-level elements.