Ketogenesis and ketolysis are two interconnected metabolic processes that play essential roles in the utilization and production of ketone bodies. Ketone bodies, including acetoacetate, β-hydroxybutyrate, and acetone, serve as alternative energy sources during periods of prolonged fasting, low carbohydrate intake, or certain metabolic conditions. This article explores the processes of ketogenesis and ketolysis, their regulation, and their significance in metabolic homeostasis.