Abstract
Inbreeding depression plays a role in the decline, endangerment, and extinction of small populations, and thus inbreeding has received much attention in conservation biology. The term inbreeding is used across distinct fields but sometimes with varying meanings. This inconsistency creates misunderstandings that complicate interpretation, hinder comparisons among studies, and obstruct effective communication of findings. In this piece, we clarify the conceptual foundations of inbreeding, showcase modern estimates, and discuss its significance and relation to classical definitions. When used together, these interpretations can offer a more comprehensive understanding of the genetic dynamics in small populations.