The Friedel-Crafts Reaction is a type of chemical reaction used to attach alkyl or acyl groups to an aromatic ring. This process typically involves the use of a catalyst, such as aluminum chloride, to facilitate the reaction between an aromatic compound and an alkyl halide or acyl halide. The result is the formation of a new carbon-carbon bond, expanding the complexity of the aromatic compound. There are two main types of Friedel-Crafts reactions: Friedel-Crafts alkylation and Friedel-Crafts acylation. Alkylation introduces an alkyl group, while acylation introduces an acyl group. Both reactions are valuable in organic synthesis for creating more complex molecules from simpler aromatic compounds.