An organic compound refers to any member of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates and carbon oxides. The study of organic compounds is termed organic chemistry. Many of these compounds, such as proteins, fats, and carbohydrates (sugars), are also of prime importance in biochemistry.
Some of the classes of organic compounds include aliphatic compounds, chains of carbon which may be modified by functional groups; aromatic hydrocarbons, compounds containing one or more benzene rings; heterocyclic compounds which include non-carbon atoms as part of a ring structure; and polymers, long chains of repeating groups.
The dividing line between organic and inorganic is contended and historically arbitrary; generally speaking, however, organic compounds are defined as those compounds which have carbon-hydrogen bonds, and inorganic compounds, those without. Thus carbonic acid is inorganic, whereas formic acid, the first fatty acid, is organic, although it could as well be called "carbonous acid" and its anhydride, carbon monoxide, is inorganic.
The name "organic" is a historical name, dating back to 19th century, when it was believed that organic compounds could only be synthesised in living organisms through vis vitalis - the "life-force".
Most pure organic compounds are artificially produced--yet it is ironic that the term "organic" is also used to describe products produced without artificial chemicals (see organic production).