Anthropomorphic Personifications
An anthropomorphic personification is a natural process endowed with human form and personality. On the Disc, personifications are fully fledged characters whose personalities have evolved beyond their "jobs". The difference between "god" and "anthropomorphic personification" in the Disc's pantheon is unclear; essentially it appears to be that a "god" is a being assigned a wide range of roles and powers by human belief, while personifications embody concepts and things that would exist whether people believed in them or not. However, Anthropomorphic Personifications of the disc would cease to exist if total belief in them stopped. (see The Hogfather.) Belief shapes how a personification manifests, not what it does. There are a number of ambiguities. For example, Death is certainly a personification (since living things die whether or not people believe they do), as are his fellow Apocralyptic (Apocryphally apocalyptic) riders Kaos, War, Pestilence and Famine. However, Fate and The Lady (i.e. Lady Luck), despite personifying concepts, are better thought of as gods, since one has to believe in fate or luck for them to exist.
Read more about this topic: Discworld Gods