Santería comes from an African religion that was brought to Cuba by slaves. It remains present to this day.
Slaves were not allowed to practice their religions, so they changed Santería to be similar to Catholicism. Catholic saints were given matching gods in Santería.
The Santería religion contains hundreds of gods, but not all are routinely worshipped. Many Cuban have figurines of Santería gods in their homes, even non-believers.
Santería does not come with the definitions of morality that many religions do. The worshipped gods do not conduct themselves in a purely virtuous way.
Ceremonies are commonly held in Cuba. New members are admitted and dress up in certain ways for the ceremony. Offerings are made to the gods as well.