Out-breeding - Breeding of unrelated animals which may be between individuals of the same breed or between individuals of different species. [1]
Out-crossing - A kind of out-breeding in which animals are mated within the same breed but having no common ancestors on either side of their pedigree upto 4-6 generations. [1]
Cross-breeding - Another type of outbreeding in which superior males of one breed are mated with superior females of another breed. [1]