(1)Inbreeding : It refers to the mating of """two closely related""" individuals within the "same breed" for 4-6 generations. ***here closely related means having common parents or ancestor okk. (2) Out breeding : This is achieved by breeding of """unrelated"""" individuals. Individuals may be of same breed but having no common ancestor for 4-6 generations ( Out crossing) or between different breeds ( cross breeding) or even different species ( Inter - specific hybridisation.) (I) Out crossing : This method involves mating of Animals within the same breed butttttthaving no common ancestor on either side of mating parbents up to 4-6 generations as in inbreeding .(ii)Cross breeding : It is practice of mating superior female of one breed with superior male of another breed. Here ""two different breeds are crossed"" that's why it is called as cross breeding (iii) Inter specific hybridisation : mating of male and females of different species .