A haploid cell is one that contains only a single set of chromosomes. In humans, a haploid cell consists of 23 chromosomes. Both sperm and egg cells are haploid.
Diploid cells generate haploid cells in a process called meiosis. Normal cell division is called mitosis and produces two identical daughter cells with the same number of chromosomes as the parent cell. Meiosis reduces the number of chromosomes by half. This process occurs in two divisions. Meiosis I halves the number of chromosomes in the diploid cell, a cell with two sets of chromosomes. Once the chromosomes are reduced, the cells go through meiosis II, which is comparable to mitosis. The two daughter cells that have half the number of chromosomes as the parent cell duplicate their chromosomes. Then, each divides and becomes two cells. Four cells with a haploid complement of chromosomes result from meiosis.