Semantics is the study of meaning in language and is primarily focused on the analysis of vocabularies technically referred to as lexicons or lexical systems. It constitutes a major field of linguistics per se and of an important companion field in anthropology called ethnoscience or, more accurately, ethnosemantics. Unlike phonology and morphology, semantics deals directly with the way in which categorization and ordering within a language's vocabulary relates to perceived objects, events, and forces in the natural and cultural worlds, and has an obvious application for understanding culture and cultural processes.

The relevant features of the external world that are recognized within a semantic system are known as referents. The terms by which they are represented in the language are called lexemes. Referents are considered as they are compartmentalized within specific topical areas called semantic domains. There are numerous domains and subdomains in a language's semantic system, which, accordingly, can never be presented with any degree of completeness. These domains, moreover, are culturally selected rather than universal categories apparent in all societies. Thus, any of the following domains might serve as an area of semantic research:

Anthropologists tend to treat those particular domains that are most relevant to their interests. Some domains, however, are important for most cultures and form major areas of specialization for semantic investigation, for example, ethnobotany, which covers the domain of the plant world, and kinship terminology, which covers the categories into which people classified as relatives and in-laws are grouped.

When a domain has been investigated exhaustively, all the lexemes appropriate to it are organized into a taxonomy, or classification system, which then forms the basis for further investigation. Analysis of taxonomies provides insights into the categories of perception inherent in a particular meaning system and the organizing principles employed to distinguish and interrelate them. The resulting semantic scheme is sometimes called a cognitive map, a guide to the world though the cultural lens of a particular society and, for some anthropologists, a depiction of the world view of its members. Folk taxonomies also serve as a basis for investigating indigenous knowledge systems, since classification is a necessary preliminary step in developing an ordered scientific understanding of a segment of reality.