This entry focuses on the discipline of genomics and its relevance to understanding the human life course. There is no unified definition of genomics, but typically, this discipline within the genetic sciences is differentiated from genetics by virtue of [Page 955]the former focusing on the structure, function, and evolution of the whole genome (the complete set of DNA defining a particular species), which defines the phenotype, or physical identity, of the organism, whereas the latter concentrates on general principles of variation and heredity in living organisms.