Cell proliferation is the process by which a cell grows and divides to produce two daughter cells. Cell proliferation leads to an exponential increase in cell number and is therefore a rapid mechanism of tissue growth. Cell proliferation requires both cell growth and cell division to occur at the same time, such that the average size of cells remains constant in the population. Cell division can occur without cell growth, producing many progressively smaller cells, while cell growth can occur without cell division to produce a single larger cell. Thus, cell proliferation is not synonymous with either cell growth or cell division, despite these terms sometimes being used interchangeably.