Before mitosis occurs the cell spends most of its time in interphase.
The first stage of mitosis is prophase. During prophase the chromotids first become visible. The nucleus membrane starts to disintegrate while the centriols move to opposites ends of the cell.
During the next phase of mitosis which is called metaphase the chromotids line up in the middle of the cell. As the dotted white line shows. The next phase is anaphase in this phase the chromotids move to opposite ends of the cell.
The last phase is telephase. In this phase a new nucleus forms around the chromotids. Now mitosis is complete and cytokenisis happens. In this phase the cell splits into two. Then End.