Elohim: the more common form in the OT; it is plural in form, emphasizing majesty. El Shaddai: God Almighty (perhaps originally, God of the mountains). Adonai: My great Lord—used for kings, but after the Exile to replace 'Yahweh' in worship.
How do we use the name of God?
When you pray, try to use this name in your prayer. When you are asking God for something call out to Him as Jehovah-Jireh, recognize God as one who can provide. We cannot ask God for something but at the same time think that He cannot do it.