Mitosis

 This phase of the cell cycle, though the shortest, is itself divided into stages:  PROPHASE, METAPHASE, ANAPHASE and TELOPHASE.  During Mitosis, nuclear cell divison takes place, each new nuceleus containing one complete set of chromosomes.  Recall that during the S phase of Interphase DNA was replicated within the nucleus in preparation for cell division.

Following Telophase, the cell itself divides by a process called Cytokinesis.