In the human body, mitosis occurs in the nucleus of the body's normal cells (the somatic cells). It does not occur in gamete cells (cells that are a part of reproduction).
Mitosis is a process that divides a single cell into two identical cells. The body uses mitosis to create new cells to replace old, damaged cells. Growth also occurs because of mitosis, which creates the additional required cells.
The process of mitosis is not perfect; mistakes can occur when the genetic material of the original cell is replicated. Errors during this process can kill cells or cause them to mutate. It is believed that mitosis errors cause some types of cancer.