The sciences are more commonly divided into three main groups, or branches: life science, which includes the study of biological life; physical science, which includes physics and chemistry; and earth science, which concerns itself with geology, meteorology and astronomy. There is some overlap between these branches.
These branches apply to the hard sciences, which maintain a high level of objectivity and methodological exactitude. Soft sciences, such as social science, or the study of human behavior and societies, are not included within these branches, and may be postulated as either a fourth branch or as an entirely separate field of study.
