The Tetragrammaton (//) or Tetragram (from Greek τετραγράμματον, meaning "[consisting of] four letters") is the four-letter Hebrew word יהוה (transliterated as YHWH), the name of the national god of Israel. The four letters, read from right to left, are yodh, he, waw, and he. While there is no consensus about the structure and etymology of the name, the form Yahweh is now accepted almost universally.
The books of the Torah and the rest of the Hebrew Bible except Esther, Ecclesiastes, and (with a possible instance in verse 8:6) the Song of Songs contain this Hebrew name. Observant Jews and those who follow Talmudic Jewish traditions do not pronounce יהוה nor do they read aloud proposed transcription forms such as Yahweh or Yehovah; instead they replace it with a different term, whether in addressing or referring to the God of Israel. Common substitutions in Hebrew are Adonai ("My Lord") or Elohim (literally "gods" but treated as singular when meaning "God") in prayer, or HaShem ("The Name") in everyday speech.