* The Chewa people: A large Bantu ethnic group primarily found in Malawi, Zambia, and Mozambique. Their language is called Chichewa.
* The Chewa language: Also known as Chichewa, is the official language of Malawi and a major language in Zambia. It belongs to the Bantu branch of the Niger-Congo language family.
So, the answer to your question depends on what you meant by "Chewa".
If you meant the people, then the language they speak is Chichewa. If you meant the language itself, then it's also called Chichewa.