Chemistry is the science of matter and its interactions with energy and itself (see physics, biology). Because of the diversity of matter, which is mostly in the form of atoms, chemists often study how atoms interact to form molecules and how molecules interact with each other. Chemistry typically is divided into several main branches. There are also several main cross-disciplinary and more specialized branches of chemistry.

Organic chemistry is the science of the structure, properties, composition, and reactions of organic compounds.

Inorganic chemistry is the branch of chemistry concerned with the properties and reactions of inorganic compounds.

The distinction between organic and inorganic disciplines is not absolute and there is much overlap, most importantly in the sub-discipline of organometallic chemistry.

Physical chemistry is the study of the physical basis of chemical systems and processes. In particular, the energetic description of diverse chemical transformations are of interest to physical chemists. Important areas of study include chemical thermodynamics, chemical kinetics, quantum chemistry, statistical mechanics, and spectroscopy.

Biochemistry is the study of the chemicals, chemical reactions and chemical interactions that take place in living organisms.

Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure.