Aryl groups are functional groups derived from aromatic compounds, which contain a benzene ring or similar structure. They are formed when one hydrogen atom from the benzene ring is replaced by another atom or group, such as a methyl or hydroxyl group. Common examples of aryl groups include phenyl (C6H5) and naphthyl (C10H7). These groups are important in organic chemistry because they influence the chemical properties and reactivity of molecules. Aryl groups can participate in various reactions, such as electrophilic aromatic substitution, and are often found in pharmaceuticals, dyes, and other industrial chemicals.