General characteristics of the penitentiary system (penal system), specific conditions of detention in correctional institutions, psychological characteristics of the personality of convicts, classification and typology of convicts are presented, characteristics of groups are given and the nature of the criminal subculture is described, aspects of preparation and adaptation of convicts to life in new conditions are disclosed. The basics of the activities of the psychological service of correctional institutions and psychological support of persons in places of deprivation of liberty are given.