A special class of Zonohedron. There are five parallelohedra with an infinity of equal and similarly situated replicas which are Space-Filling Polyhedra: the Cube, Elongated Dodecahedron, hexagonal Prism, Rhombic Dodecahedron, and Truncated Octahedron.
See also Parallelotope, Space-Filling Polyhedron
Coxeter, H. S. M. Regular Polytopes, 3rd ed. New York: Dover, p. 29, 1973.