Worlds and soul levels

These names are taught both individually and inside אבי״ע, בי״ע, נר״ן, נרנח״י. The learner should be able to move in either direction: see an acronym and expand it, or see a full term and recognize the group to which it belongs. The English/transliteration is an identification aid; the specific correspondence of a soul level to a world or Partzuf must come from the passage being studied.