Nuba is a collective term used here for the peoples who inhabit the Nuba Mountains of South Kordofan state, in Sudan. Although the term is used to describe them as if they composed a single group, the Nuba are multiple distinct peoples and speak different languages. Estimates of the Nuba population vary widely; the Sudanese government estimated that they numbered 1.07 million in 2003.
In Sudan's 1993 census, the population was calculated at 25 million. No comprehensive census has been carried out since that time due to the civil war. Estimates of Sudan, including the population of South Sudan, ranged from 37 million (United Nations estimate) to 45 million (CIA estimate). Since the secession of South Sudan in July 2011, estimates place the current population of Sudan at a little over 30 million. The population of metropolitan Khartoum (including Khartoum, Omdurman, and Khartoum North) is growing rapidly and ranges from six to seven million, including around two million displaced persons from the southern war zone as well as western and eastern drought-affected areas.