Hausa is spoken in the northern half of Nigeria, Ghana, Cameroon, Benin and Togo, and the southern half of Niger, Chad and Sudan, with significant minorities in Ivory Coast.

Hausa is the most widely spoken language within the Chadic branch of languages. Ethnologue estimated that it was spoken as a first language by some 47 million people and as a second language by another 25 million, bringing the total number of Hausa speakers to an estimated 72 million.

The Hausa traditionally live in small villages as well as in precolonial towns and cities where they grow crops, raise livestock including cattle as well as engage in trade, both local and long distance across Africa.

Because the vast majority of Hausa speakers are Muslims, many attempted to embark on the Hajj pilgrimage, a requirement of all Muslims who are able. On the way to or back from the Hijaz region, many settled. For example, many Hausa in Saudi Arabia identify as both Hausa and Afro-Arab. In the Arab world, the surname "Hausawi" (alternatively spelled "Hawsawi") is an indicator of Hausa ancestry.

Christians represent less than 1% of the Hausa people with 9 of the 16 people groups listed as "frontier" by the Joshua Project, meaning they have had little or no contact with Christianity. The Bible is available in the language and several dialects.

Sources:
Wikipedia
The Joshua Project