The Afro-Brazilian religions carry a West African arrangement into Brazil and reorganise it around the terreiro, the house. A supreme being, Olorun in the Ketu tradition, stands at the origin and is not served directly; the orixas are served, each with characteristic domains, colours, foods, rhythms and days, and each house holds the ones that belong to it.
Ancestry runs through the house rather than through birth. A person belongs to a terreiro, and to the priest or priestess who heads it, in a line of religious descent that is traced and named, and the house's own history is part of its authority.
Under slavery and for a long time afterwards the practice was illegal or policed, and the identification of orixas with Catholic saints belongs to that history. It permitted observance to continue in the open, and it has since become part of the religious texture rather than a disguise that can simply be removed.
The traditions are plural and they are not interchangeable. Candomble has several nations with different African origins and liturgical languages; Umbanda, formed in the twentieth century, incorporates spiritist and indigenous elements and works with a different range of entities. The atlas keeps them distinct where it can.
These are living religions, and the atlas lists them as restricted traditions. Terreiro initiation is closed. What passes inside it is not reproduced here.