For eukaryotes, the term mating is most often used to describe the pairing of opposite-sex or hermaphrodite organisms, usually for the purposes of sex

The term mating is also applied to related processes in bacteria, archaea and viruses. Mating in these cases involves the pairing of individuals, accompanied by the pairing of their homologous chromosomes and then exchange of genomic information leading to formation of recombinant progeny (see Mating systems).