The term "K-group" typically refers to a classification system used in various fields, including biology and sociology. In biology, it can denote a group of organisms that share similar characteristics or genetic traits. In sociology, it may describe a category of individuals who share common social or cultural attributes. In the context of mathematics, "K-group" can also refer to a specific type of group in algebraic topology, which is used to study the properties of spaces. These groups help mathematicians understand complex structures by analyzing their underlying symmetries and relationships.