A hybrid is the product of mating between individuals of different species or strains. The word is most common when talking about animals and plants.
Mules are hybrid animals. The femaleparent is a horse and the male parent is a donkey. The result, a mule, is sterile. Not all hybrids are sterile. Many garden plants and crop plants are hybrids. New species are sometimes formed from hybrids between two other species.