Traditions understand their rites in different ways, as effecting a real change (a sacrament that conveys grace, an initiation that alters status), as commemorating an event, as maintaining a cosmic or social order, or as a means of purification or protection, and the entries record the tradition's own understanding.
The rituals group by function (initiatory, calendrical, funerary, purification, sacrificial, devotional and the rest), so a reader can compare how different traditions mark the same passage. The ongoing disciplines of religious life, as opposed to set rites, are treated as practices.