Heterogeneity (from the Greek ἕτερος héteros 'different', 'different' and γένεσις génesis 'generation', 'birth') denotes the inconsistency of the elements of a set or the components of a body. The term occurs in all natural and human sciences. The superordinate system (body, total quantity, etc.) is referred to as heterogeneous , not its individual components.
In contrast to heterogeneity, there is homogeneity . In a heterogeneous system, the properties at interfaces can change abruptly or differ greatly from individual to individual. In a heterogeneous mixture, in contrast to a homogeneous mixture, the different particles can be distinguished with optical aids (the eye or with the aid of a microscope).
As inhomogeneous are generally referred to systems with less deviation from the uniformity, for example, a material with uniform components, but from place to place varying density . The use of the word differs depending on the subject. In the figure, inhomogeneity is shown on the right and heterogeneity in the middle.
For heterogeneous systems or population groups, the following applies: A small sample cannot be used to determine the totality.