Organic compounds are chemical substances that primarily contain carbon atoms, often bonded with hydrogen, oxygen, nitrogen, and other elements. They are the building blocks of life and are found in all living organisms. Common examples include carbohydrates, proteins, lipids, and nucleic acids, which play essential roles in biological processes. These compounds can be classified into various categories, such as aliphatic and aromatic compounds, based on their structure. Organic compounds can be naturally occurring, like those found in plants and animals, or synthetically produced in laboratories for use in pharmaceuticals, plastics, and other materials.