Maybe a more familiar way to put this would be a visitation with the Lord. That’s what I believe the old school called it. This is when God pricks your heart to let you know that He wants to meet with you for whatever reason is on His heart.
Jacob is one of the first examples that comes to mind when I think about meeting with the Lord. God met with Jacob giving him a dream showing him what He was to do with him, and that He was to be with him in the process (Read Genesis 28:10-20).
Jacob made a memorial to the Lord, and his confidence in God was strengthened. Often God uses a dream at night to speak with or visit His people when we are really busy, and unbeknownst to His voice.