The cell cycle is the ordered series of events a eukaryotic cell goes through to grow, duplicate its genetic material, and divide into two new daughter cells. Its primary function is to accurately copy the cell's vast amount of DNA and precisely segregate the copies into two genetically identical daughter cells. The cell cycle is divided into two main phases: Interphase (growth and DNA replication) and the Mitotic Phase (cell division). The cell cycle is highly regulated by a control system to ensure events occur in the correct sequence and only when conditions are right. This control relies on checkpoints and key regulatory molecules. The progression through the cycle is primarily driven by the fluctuating activity of two types of proteins: Cyclins are proteins whose concentrations change (increase and decrease) throughout the cell cycle. Cyclin-Dependent Kinases (CDKs): Enzymes whose activity depends on binding to a specific cyclin. The active CDK complex phosphorylates target proteins, triggering the events of the next cell cycle stage.