French sociologist Émile Durkheim introduced the notion of collective effervescent in his book The Elementary Forms of Religious Life (1912).
Collective effervescence is the energy, exuberance, and sense of unity that people feel when participating in communal activities, like rituals, ceremonies, or events. People transcend their personal identities, transgress societal norms, and experience the sacred.
Think concerts, religious rituals, and powerful, once-in-a-lifetime shared experiences throughout history. People transcend themselves in such moments and experience an almost collective, sacred, emotion.
Collective effervescence often ties into theological studies since the religious can be, in a sense, that higher plane of emotion, or at least a route to such via ceremony, ritual, totems, and sacred objects.
So, hope you found that useful! Check out my full Religion 101 article list (useful for studying, or just learning!) here.