Visions and Dreams
"And it shall come to pass afterward, that I will pour out My Spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions: And also upon the servants and upon the handmaids in those days will I pour out My Spirit. And I will show wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of The Lord come. And it shall come to pass, that whosoever shall call on the name of The Lord shall be delivered: for in mount Zion [see also Who, What or Where Is Zion?] and in Jerusalem shall be deliverance, as The Lord hath said, and in the remnant whom The Lord shall call." (Joel 2:28-32 KJV)
"understanding in all visions and dreams"
The prophecy, about prophecy, quoted above is one of the most joyous of the Scriptures because it refers to a future time when The Lord will be known throughout the world. God-inspired dreams and visions have already been happening for a long time however.
Visions and dreams could merely be a means to personally direct someone on the right path, sometimes without their even realizing that it's from God, as in this example from Job.
"For God speaketh once, yea twice, yet man perceiveth it not. In a dream, in a vision of the night, when deep sleep falleth upon men, in slumberings upon the bed; Then he openeth the ears of men, and sealeth their instruction, That he may withdraw man from his purpose, and hide pride from man. He keepeth back his soul from the pit, and his life from perishing by the sword." (Job 33:14-18 KJV)
Visions and dreams could be far more than that however. Daniel was one of the greatest prophets while still a youth.
"As for these four children, God gave them knowledge and skill in all learning and wisdom: and Daniel had understanding in all visions and dreams." (Daniel 1:17 KJV)
Daniel's God-given "understanding in all visions and dreams" didn't just mean his own. One of the most specific prophecies (that includes the rise and fall of end-time Rome, and the return of Jesus Christ - see the Fact Finder question below) of the Bible was given in a dream to King Nebuchadnezzar of Babylon, a dream that was explained by Daniel (again, see the Fact Finder question below).
"But there is a God in heaven that revealeth secrets, and maketh known to the king Nebuchadnezzar what shall be in the latter days.Thy dream, and the visions of thy head upon thy bed, are these;
As for thee, O king, thy thoughts came into thy mind upon thy bed, what should come to pass hereafter: and he that revealeth secrets maketh known to thee what shall come to pass. But as for me, this secret is not revealed to me for any wisdom that I have more than any living, but for their sakes that shall make known the interpretation to the king, and that thou mightest know the thoughts of thy heart.
Thou, O king, sawest, and behold a great image. This great image, whose brightness was excellent, stood before thee; and the form thereof was terrible. This image's head was of fine gold, his breast and his arms of silver, his belly and his thighs of brass, His legs of iron, his feet part of iron and part of clay. Thou sawest till that a stone was cut out without hands, which smote the image upon his feet that were of iron and clay, and brake them to pieces. Then was the iron, the clay, the brass, the silver, and the gold, broken to pieces together, and became like the chaff of the summer threshingfloors; and the wind carried them away, that no place was found for them: and the stone that smote the image became a great mountain, and filled the whole earth.
This is the dream; and we will tell the interpretation thereof before the king" (Daniel 2:28-38 KJV)
When Miriam and Aaron jealously opposed their brother Moses ("hath He not spoken also by us?"), The Lord replied by saying that He spoke to Moses by even more than visions and dreams.
"And Miriam and Aaron spake against Moses because of the Ethiopian woman whom he had married: for he had married an Ethiopian woman. And they said, Hath The Lord indeed spoken only by Moses? Hath he not spoken also by us? And The Lord heard it.
Now the man Moses [see also The Education Of Moses] was very meek, above all the men which were upon the face of the earth.
And The Lord spake suddenly unto Moses, and unto Aaron, and unto Miriam, Come out ye three unto the tabernacle of the congregation. And they three came out. And The Lord came down in the pillar of the cloud, and stood in the door of the tabernacle, and called Aaron and Miriam: and they both came forth. And he said, Hear now my words:
If there be a prophet among you, I The Lord will make myself known unto him in a vision, and will speak unto him in a dream. My servant Moses is not so, who is faithful in all mine house. With him will I speak mouth to mouth, even apparently, and not in dark speeches; and the similitude of The Lord shall he behold: wherefore then were ye not afraid to speak against my servant Moses?" (Numbers 12:1-8 KJV)
Fact Finder: What dream did Daniel explain to King Nebuchadnezzar?