Here's why:

* Diploid means "having two sets of chromosomes."

* Chromosomes are structures within cells that carry genetic information.

* Homologous chromosomes are pairs of chromosomes that carry the same genes but may have different versions of those genes (alleles).

So, a diploid cell has two sets of chromosomes, where each set contains one chromosome from each homologous pair. This is the typical state of most cells in the body of multicellular organisms. For example, human body cells have 23 pairs of chromosomes, making them diploid with a total of 46 chromosomes.

Contrast this with haploid cells:

* Haploid cells have only one set of chromosomes.

* Gametes (sperm and egg cells) are haploid, containing only one chromosome from each homologous pair.

* When a sperm and egg cell fuse during fertilization, they create a diploid zygote with a complete set of chromosomes.