From BiblePortal Wikipedia

Visions [1]

By means of visions God often vouchsafed to make known His will. When Samuel was a child, before the word of Jehovah was revealed to him, for a time 'there was no open vision.'  1 Samuel 3:1,15 . With the prophets they were frequently employed: more than twenty times we read of them in Daniel. In the future when the Spirit will be poured out, Israel's sons and daughters will prophesy; the old men will dream dreams, and the young men will see visions.  Joel 2:28;  Acts 2:17 . The book of Revelation is a series of visions.  Revelation 1:2 .