The Four-Fields Approach
Modern Anthropology in the United States and United Kingdom, as well as in much of the Western World, has been influenced by the "Four Field Approach". This approach, originally popularized by Franz Boas (the "Father of American/Modern Anthropology"), focuses on four distinct sub-fields within the larger discipline of anthropology: the cultural, physical, linguistic, and archaeological studies.
Chances are, unless you are taking introductory courses or ones focused on a dissertation/thesis, your Anthropology class(es) fits into one of these four afformentioned fields. For example, "Language Thought and Culture" (an introductory linguistic course) would fit neatly into its respective field. "Human Origins" would be a physical anthropology course, "The Archaeology of Mesoamerica" would be an archaeological one, and "Medical Anthropology" would be a cultural anthropology course.
Physical anthropology courses (also known as "biological anthropology" classes) focus on the development, status, and prospects of the human species with respect to its physical structure. Biological anthropology, which is sometimes differentiated from the larger field of phyisical anthropology, also seeks to analyze human genetics and biology from an interdisciplinary perspective. Cultural anthropology, the other large pillar of the discipline, studies cultural differences and similarities through scientific fieldwork. Social anthropology, often combined with cultural anthropology but seeking to gain status as the "fifth field of anthropology", studies the interactions between and inside of social groups. Social anthropologists examine political, economic, and cultural institutions and how they interact with one another to provide the larger structure of society. Archaeologists, holding some similarities with physicial anthropologists, study human society through its material remains. Linguistic anthropologists, often thought of as holding less importance than the physical, cultural, and archaeological sub-fields, explore the vast array of human communication and how it influences society.