Methods of inferring the population structure‎, ‎its applications in identifying disease models as well as foresighting the physical and mental situation of human beings have been finding ever-increasing importance‎. ‎In this article‎, ‎first‎, ‎motivation and significance of studying the problem of population structure is explained‎. ‎In the next section‎, ‎the applications of inference of population structure in biology and the treatment of various diseases are described‎. ‎Afterward‎, ‎the methods of inferring the population structure as well as detecting the disease model correspond to each subpopulation‎, ‎for populations whose members are admixture or not‎, ‎are described separately‎. ‎To this end‎, ‎the methods of inferring the population structure through the Bayesian approach are emphasized and the reasons for the superiority of Bayesian methods are illustrated‎.