Out-breeding refers to mating or breeding outside of a particular group or population. Synonyms for out-breeding may include crossbreeding, outcrossing, interbreeding, intercrossing, and hybridization. Crossbreeding refers to the process of breeding individuals from two different purebred or hybrid populations or breeds. Outcrossing, on the other hand, refers to mating individuals belonging to separate populations within the same breed or species. Intercrossing describes the process of breeding individuals from two distinct populations with different traits. Finally, hybridization refers to the crossing of individuals from different species or genera. All these synonyms for out-breeding play an important role in maintaining genetic diversity in populations and improving their physical traits.