This is a heading over many peoples, languages and traditions, and the atlas holds it as a heading rather than as a religion. The Akan, Igbo, Dogon, Serer, Mende and dozens of others are distinct, and where the atlas can name a tradition it does so separately.
What recurs widely enough across the region to be worth stating as a shape is a supreme creator who is not the focus of cult. The high god made the world and is spoken of with reverence, and observance goes to a working order of powers below: deities of rivers, of the earth, of thunder, of iron and of the market, together with the ancestors of the lineage. The creator's remoteness is not neglect in the tradition's own terms but a description of how the world is arranged.
Below that, the organising principle is locality and lineage. A deity belongs to a place or to a descent group, and a person's obligations follow from where and to whom they were born. There is rarely a single roster that a whole people would recognise as complete.
The ancestors are not a separate department. They are part of the working order, addressed, fed and consulted, and a distinguished ancestor may over time be served in a way that is not sharply distinguishable from a deity.
These are living traditions with living custodians, several of them listed by this atlas as restricted. What is transmitted within an initiated office is not reproduced here.