Short answers, pulled from the story.
A ritual is a repeated, structured sequence of actions or behaviors that alters the internal or external state of an individual, group, or environment, regardless of conscious understanding, emotional context, or symbolic meaning. Rituals are a feature of all known human societies and range from worship rites and coronations to marriages, funerals, and even common acts like hand-shaking.
The word ritual derives from the Latin ritualis, meaning that which pertains to rite, or ritus, which in Roman usage was the proven and correct way of doing something. The concept of ritus may relate to the Sanskrit rta, the visible order of Vedic religion. The word ritual was first recorded in English in 1570.
Arnold van Gennep stated that rites of passage are marked by three stages: separation, transition, and incorporation. In separation, initiates are cut from their old identities; in transition they are betwixt and between; and in incorporation they are symbolically confirmed in a new identity and community.
Liminality is the condition of ambiguity or disorientation Victor Turner identified in the transition stage of a rite of passage, when initiates have been stripped of their old identities but have not yet acquired their new one. Turner called these initiates threshold people, and argued the role ambiguity creates communitas, an emotional bond of community.
Dulaney and Fiske found that ethnographic descriptions of cultural rituals contained around five times more OCD-like content, such as cleaning objects and emphasis on the number or order of actions, than descriptions of other activities like work. Lienard and Boyer suggested the overlap stems from a shared mental process they call hazard precaution.
Catherine Bell argued that rituals can be characterized by formalism, traditionalism, invariance, rule-governance, sacral symbolism, and performance. She also shifted attention from ritual as a fixed category toward the process of ritualization, a way of acting designed to distinguish and privilege what is being done compared to ordinary activities.