What is the difference between cytokinesis and karyokinesis? Which process needs to be more precise ...

Karyokinesis is the equal partitioning of the chromosomal material in the nucleus of the parental cell between the nuclei of the two daughter cells. This process requires first that each of the chromosomes in the nucleus be fully and accurately duplicated and then that the duplicate copies of each chromosome be separated so that one copy goes to the nucleus of one daughter cell and the second copy goes to the other daughter nucleus. Karyokinesis is followed by cytokinesis, the partitioning of the cytoplasmic contents of the parental cell into the daughter cells.
Cytokinesis does not demand the same degree of equivalency required in karyokinesis. The cytoplasm of the parental cell contains an abundance of the proteins and organelles that the daughter cells require in order to function, so the division of this material need not be equal.