The tetragrammaton (Greek for ‘having four letters’) YHWH is the proper name of the national God of the Israelites. It was probably pronounced ‘Yahwe’. The name may have been derived from a verb meaning ‘to be’, ‘to become’, or ‘to come to pass’ (Exodus 3:14). All the books in the Hebrew Bible, except Esther and Song of Songs, have the word YHWH. In many places the word ‘Elohim‘ (meaning ‘God’) is used as a substitute.
Different enunciations of YHWH have been used, such as ‘the LORD’ and ‘Yahweh.’
Expressions related to YHWH are: the LORD (Deuteronomy 33:2), the LORD of (the) hosts (Hosea 12:5 [Hebrew text 12:6]); the LORD of hosts (Malachi 2:15), the spirit of the Lord God (Isaiah 61:1), the terrible Day of the LORD (Joel 2:31 [Hebrew text 3:3]), etc.