Organic reaction mechanisms describe the step-by-step process by which reactants are converted into products in organic chemistry. These mechanisms explain how bonds are broken and formed during a reaction, including the movement of electrons. Key concepts include nucleophilic and electrophilic attacks, intermediates, and transition states. Understanding these mechanisms helps predict reaction outcomes, optimize reaction conditions, and design new synthetic pathways. Mechanisms are often classified into types, such as substitution, elimination, and addition reactions, each involving different patterns of electron flow.