A gamete contains half of the genetic information needed to produce a new individual, so this means that each gamete has 23 chromosomes. A normal human cell contains 46 chromosomes, which are two sets of the 23 base chromosomes found in each gamete.
Each parent cell has the full 46 chromosomes, but during the process of meiosis, the cells are split to produce daughter cells with just the base 23. If the cells did not split and reduce in the number of chromosomes, the new individual would either not survive due to having 92 chromosomes or be severely disabled. The gametes produced by a female are larger than those produced by males. This is referred to as heterogamy.