The form of cell division that creates gametes, or sex cells (eggs or sperm) is called meiosis. It is a special form of reproduction that results in four next-generation cells, rather than just two, from each cell.
As with so many scientific terms, the word meiosis comes from the Greek, in this case meíōsis, which means "a lessening." This idea makes sense, as meiosis creates cells with half the chromosomes than the original. These cells are specifically for reproduction, and then take additional genetic material from the other parent cell. The actual discovery of meiosis happened in 1883, when Belgian scientist Edouard Van Beneden noticed that sex cells had a different way of dividing than did other cells.