During the 1700s and early 1800s, most chemists believed that there were two main branches of chemistry: organic and inorganic. These two branches still exist today, however, the rules governing their classification have changed.

Organic Chemistry is the study of the compounds of carbon. This branch of chemistry is important to the petrochemical, pharmaceutical and textile industries. All living organisms have traces of carbon.

Inorganic Chemistry is the study of chemical elements and their compounds except carbon.

Physical Chemistry deals with the relations between the physical properties of substances and their chemical formations along with their changes.

Biochemistry is a science that fused biology and chemistry. It is concerned with the composition and chemical reactions that occur in the formation of living species.

Analytical Chemistry deals mostly with the composition of substances. It seeks to improve means of measuring chemical composition of natural and artificial materials. In medicine, this is the basis for clinical laboratory tests for disease diagnosis. The nutritional value of the food we eat and the examination of many household products is determined through chemical analysis.