What is the stage of the cell cycle during which DNA replication occurs?

The stage of the cell cycle during which DNA replication occurs is the S phase, which stands for "synthesis phase." During this phase, the cell replicates its entire set of DNA, ensuring that each daughter cell will receive an identical copy of the genetic material when the cell divides. This is a critical process because it sets the foundation for cellular division, allowing both new cells to have the same genetic information as the original cell. The S phase typically occurs after the G1 phase, where the cell grows and prepares for DNA synthesis, and before the G2 phase, where the cell continues to grow and prepares for mitosis. Cell division cannot occur successfully without this essential step, as it ensures that the genetic material is accurately copied and maintained throughout cell generations.