Coexistence
Coexistence is the property of things existing at the same time and in a proximity close enough to affect each other, without causing harm to one another. The term is often used with respect to people of different persuasions existing together, particularly where there is some history of antipathy or violence between those groups. Coexistence can be observed to a property of all systems in which different aspects capable of interacting with each other exist at the same time. As one source asserts, "even at the molecular level, existence is always already coexistence". Nonliving things can also be characterized as coexisting where multiple kinds of such things exist in the same space, with the term having been used for things as disparate as different kinds of dunes on Mars, and black holes existing in the same region of space as dense nuclear star clusters.