Yahweh of hosts, God of hosts, host of, Lord of hosts

Definition:

The terms "Yahweh of hosts" and "God of hosts" are titles that express God's authority over the thousands of angels who obey him.

The term "host" or "hosts" is a word that refers to a large number of something, such as an army of people or the massive number of stars. It can also refer to all the many spirit beings, including evil spirits. The context makes it clear what is being referred to.
Phrases similar to "host of the heavens" refer to all the stars, planets and other heavenly bodies.
In the New Testament, the phrase, "Lord of hosts" means the same as "Yahweh of hosts" but it cannot be translated that way since the Hebrew word "Yahweh" is not used in the New Testament.

Ways to translate "Yahweh of hosts" could include, "Yahweh, who rules all the angels" or "Yahweh, the ruler over armies of angels" or "Yahweh, the ruler of all creation."
The phrase "of hosts" in the terms "God of hosts" and "Lord of hosts" would be translated the same way as in the phrase "Yahweh of hosts" above.
Certain churches do not accept the literal term "Yahweh" and prefer to use the capitalized word, "LORD" instead, following the tradition of many Bible versions. For these churches, a translation of the term "LORD of hosts" would be used in the Old Testament for "Yahweh of hosts."