The primary subject of study in anthropology is the examination of humans, their societies, cultures, and biological aspects over time and across different regions. Anthropology is broadly divided into four subfields: cultural anthropology, which focuses on social customs and cultural practices; archaeological anthropology, which studies past human societies through material remains; linguistic anthropology, which explores the relationship between language and culture; and physical or biological anthropology, which investigates human biological diversity and evolution. The holistic approach of anthropology allows for a comprehensive understanding of humans' complex interactions within their environments and societies.