A diploid organism or cell has two sets of chromosomes. This means that each chromosome has a corresponding pair, one from each parent. This is in contrast to haploid organisms or cells, which have only one set of chromosomes.

Here's a breakdown:

* Diploid: Two sets of chromosomes (2n)

* Haploid: One set of chromosomes (n)

Most animals and plants are diploid, while gametes (sperm and egg cells) are haploid.