AbstractIn the most general sense, a factor of a graph G is just a spanning subgraph of G and a graph factorization of G is a partition of the edges of G into factors. However, as we shall see in the present paper, even this extremely general definition does not capture all the factor and factorization problems that have been studied in graph theory. Several previous survey papers have been written on this subject [F. Chung, R. Graham, Recent results in graph decompositions, London Mathematical Society, Lecture Note Series, vol. 52, Cambridge University Press, 1981, pp. 103–123; J. Akiyama, M. Kano, Factors and factorizations of graphs—a survey, J. Graph Theory 9 (1985) 1–42; L. Volkmann, Regular graphs, regular factors, and the impact of P...