This process begins during the late stage of mitosis (Telophase) and meiosis (Telophase II). In animal cells (and in some plant cells) it is marked by a constriction of the cell membrane called the cleavage furrow. In most plant cells it happens when an expanding cell plate forms across the center of the cytoplasm called the phragmoplast.
Word origin: Greek kyto-, comb. form of kýtos container, receptacle, body + Greek kīnēsis, movement.
Related forms: cytokinetic (adjective).