General morphological as well as developmental organization of an organism.

Different , for example, possess different body plans. See, for example, the variations in body plans as associated with members of the Radiata and the Bilateria as well as parazoans versus eumetazoans versus acoelomates, pseudocoelmates, and coelomates.

See also and .

The following video introduces the simpler, animals, focusing on differences in basic body plans, but note that it totally gets wrong the of members of phylum Platyhelminthes, which have single openings to their gastrovascular cavity rather than two; ignore, that is, 5:05 through 5:10 of the video:

This video considers instead :