This is probably going to be long, and I’m probably only going to touch the surface, if that, on what these traditions are. So here goes. Please don’t believe that these simplistic answers explain the intricacies of these traditions, because they won’t.
Espiritsmo, Santeria and 21 Divisions are three different religious traditions. There are several religious traditions that evolved in Latin America namely the Caribbean, and Brazil Many of the religious traditions are African in origin. Here’s a brief blurb about the three I’ve grown up with.
Espiritismo is a religious tradition that believes people are able to communicate and work with spirits. Much of Espiritsmo, Espiritismo Cruzado and Mesa Blanca (another very similar tradition, some people say they’re the same but I believe they have key differences) uses the teachings of Allan Kardec, a French spiritist who was able to write down very useful techniques in conducting communication with spirits. We have the belief that everyone has spiritual guides, and a spiritual court which consists of ancestors, and spirits that are not ancestors.
This tradition is NOT Santeria, it is NOT 21 Divisions, it is NOT Vodou. Although a person may be involved with all three traditions (and possibly more)
Santeria is specifically Yoruba in Origin, and developed in the Caribbean (namely Cuba) with a combination of indigenous and to some extent, European influences. the most part of the religion is Yoruba. Here, we believe that The supreme God and the deities known as Orishas are present. Each Orisha has a specific role in nature, and are in charge of different forces. People are able to communicate with the ancestors (very important in Santeria) and with the Orishas to understand their place in the world, and how to understand God’s (Olodumare) will. This tradition is very initiatory and there are roles people play in their communities.
21 Divisions/ Dominican Vudú is a form of Vodou similar to Haitian Vodou that is west African ( Fon, Dahomean, Kongo, Yoruba, and other African ethnic groups) i believe mostly Dahomean and Fon.
Haitian Vodou and Dominican 21 divisions can be seen as the same, because 21 divisions is thought to be from one of the first and oldest schools of Vodou on the island. There are houses on both parts of the island that are derived from this particular Tcha Tcha lineage.
But they are different as they evolved to fit the culture and society.
Taino and Catholic beliefs are also very important.
The fundamental belief of Vudu is the belief in the supreme god, and the deities called Loas/ Misterios. People learn to work with the Misterios, seek guidance, and healing.
Although similar, Santeria and 21 divisions/ Vodou and all these other African derived religions with African deities, it is important to make sure we understand that a deity in one tradition is never the same in another. E.g. Papa Legba is not Eleggua. Even though they may have similar origins these traditions are separate and have their very specific way of worship.
These traditions should be known to be separate ones even though most people are involved with more than one.
These religions have faced lots of scrutiny because of white supremacy, but essentially, they are all traditions of resistance.