Haploid describes a cell that contains a single set of chromosomes that are not paired. The term haploid can also refer to the number of chromosomes in egg or sperm cells, which are also called gametes. In humans, gametes are haploid cells that contain 23 chromosomes, each of which a one of a chromosome pair that exists in diplod cells.

The term monoploid refers to a cell or an organism that has a single set of chromosomes.

A distinction should be made between monoploidy and haploidy. Monoploids have a single basic set of chromosomes e.g. 2n = x = 7 in barley or 2n = x = 10 in corn. Haploids, on the other hand represent individuals having half the somatic chromosome number found in normal individual. Therefore, individuals having 2n = 3x = 21 in wheat would also be haploids(not monoploid).