Concordance

In publishing, a concordance is an alphabetical list of the key words from a text showing their meanings. Concordances are rare in old large books because of the time and effort required to compile them, but more commonly arise in modern computer-generated applications. A concordance is a sort of cross-referenced index, but in (sometimes very much) more detail than the standard index of chapters and subjects typically shown before the main content. There are other more complex and different meanings of the word concordance relating to various technical applications (mathematics, genetics, etc) where often the meanings concern duality or cross-referencing of some sort.