When does DNA replication occur?

DNA replication occurs during the synthesis (S) phase of the cell cycle, which is a part of interphase. Interphase is the phase in the cell cycle where the cell grows, performs its normal functions, and prepares for cell division. The S phase specifically focuses on DNA replication, ensuring that each daughter cell will receive an identical copy of the genetic material. Replication must happen before mitosis (in eukaryotic cells) or binary fission (in prokaryotic cells) can occur, allowing for the accurate distribution of genetic information.