The vocabulary is the part of the work everyone uses, whether or not they accept the theory it came from. A hierophany is any showing of the sacred in something ordinary, a stone, a tree, a person, and the term is deliberately wider than theophany because it does not require a god. Sacred space is not homogeneous: it has a centre, an axis mundi where the levels of the cosmos meet, and orientation from that centre is what makes a world habitable. Sacred time is not the time of the calendar but the time of the founding events, re-entered through festival, so that the year begins again rather than merely continues.
Out of these he built a large claim about history. Archaic societies, he argued, understood events as repetitions of exemplary models and could therefore bear what happened to them. The modern refusal of that structure leaves people exposed to what he called the terror of history, a linear time with no renewal in it. The Myth of the Eternal Return is the compact statement, The Sacred and the Profane the introduction, and Shamanism the fullest application to a single body of material.
The method is morphological. It sorts phenomena from everywhere by structure rather than by descent, which is why he can put a Siberian pole beside an Indian pillar beside a Christian cross, and it is also why historians of particular traditions have always found him difficult to use.