A polyglot is a book that contains side-by-side versions of the same text in several different languages. Some editions of the Bible or its parts are polyglots, in which the Hebrew and Greek originals are exhibited along with historical translations. Polyglots are useful for studying the history of the text and its interpretation.
Genoa psalter of 1516, edited by Agostino Giustiniani, Bishop of Nebbio
A parallel text is a text placed alongside its translation or translations. Parallel text alignment is the identification of the corresponding sentences in both halves of the parallel text. The Loeb Classical Library and the Clay Sanskrit Library are two examples of dual-language series of texts. Reference Bibles may contain the original languages and a translation, or several translations by themselves, for ease of comparison and study; Origen's Hexapla placed six versions of the Old Testament side by side. A famous example is the Rosetta Stone, whose discovery allowed the Ancient Egyptian language to begin being deciphered.
The Rosetta Stone, a stele engraved with the same decree in both of the Ancient Egyptian scripts as well as Ancient Greek. Its discovery was key to deciphering the Ancient Egyptian language.
