What is the end result of mitosis and cytokinesis? why is this so important?

The end result of mitosis is a cell that is exactly the same as the original cell. So, if you have Cell A and cell A goes through mitosis and produces cell B... Cell B is an exact clone/replica of cell A with NO VARIATIONS. It's literally like cloning (Asexual reproduction).

Cytokinesis is part of the cell cycle, it is the last stage where a plate forms between both the cells to separate them from each other and to form two individual cells. 

Mitosis is important because it is a fast way of producing replicas of cells. Cytokinesis is important to differentiate or create boundaries between the cells.