A vision is a picture or a series of pictures that God gives you while you are awake. Dreams are pictures that you receive while you are asleep. Sometimes people may call this a night vision. A better way to understand this is that they had a literal dream. Dreams are symbolic, while visions are much more literal in their meaning. Visions will still take on God's language but are much easier to interpret and understand. There are many different types of visions. Here are just three of them:
Open-eye vision. When this happens your eyes will be open and the Spiritual realm supersedes your natural vision and you begin to see spiritual things unfold right before you like a movie.
Closed-eye vision This one is more common. This can happen while you are in prayer with your eyes closed and you begin to see pictures or just one picture. When this happens you still are aware of what is going on around you and if someone came up and spoke to you it would not stop what you are seeing. 
Snap-shot vision This happens more often when praying for someone and see the picture appear before your eyes. For the most part, this happens when your eyes are closed but can happen when your eyes are open. You will find that if you see a picture with your eyes open you can close your eyes to see the picture more clearly. If you share the picture with the one whom you are praying for, then this can become a prophetic word.

The Word says in the last days the Holy Spirit will be giving many visions and dreams.  “In the last days,” God said, “I will pour out my Holy Spirit upon all mankind, and your sons and daughters shall prophesy, and your young men shall see visions, and your old men dream dreams.” (Acts 2:17 TLB)

Visions are a special and unique way of hearing from the Lord.  Some speak of vision as a general term, as in visualizing a future perspective, or goal.  However, the Greek and Hebrew refer to vision as sight. 

Vision; gaze, look, behold, see, sight, and view. 

[2375/2377 Heb Strong’s and 3706/3705 Gk Strong’s]

A Biblical vision is a literal, spiritual and sometimes a physical happening.   It’s not a product of the mind, imagination or logic.  Receiving a vision is a gift from the Lord: an experience of sight, not the imagination.  For purposes of definitions there are 5 types of visions:

1.  Pictures, like a still photograph, on the screen of the mind.  (In my rhema, I call them PIX:)

2.  Visions which are moving scenes.

3.  Visions of gazing wonder which are like trances.

4.  Visions through the opening of the literal eyes.

5.  Being carried away in the Spirit which is revelatory experience

The following is a list of Biblical references about the purposes of visions:

1.  Encouragement, hope, and promise

(To Abram)  Genesis 15:1-6

2.Announcement of judgment

(To Samuel about Eli)  1 Samuel  3:1-18

3.Reveals secrets and an interpretation of a dream  (To Daniel)  Daniel  2:19 

4.Announcement of a servant’s calling

(To Zacharias for John)  Luke 1:22    

5.Announcement of good tidings

(The women saw a vision of angels announcing Jesus was alive.)  Luke 24:23 

6.Guidance and explicit instructions

(To Ananias for Saul)  Acts 9:10  

7.Changes an opinion and gives an assignment

(To Peter about the Gentiles)  Acts 11:5-10

8.Guidance to change locations

(For Paul to go to Macedonia)  Acts 16:9  

Usually, if someone participates in a vision, the responses are evoked by His Spirit, they come out of our spirit and not our natural mind, will or emotions.  Visions come from the realm of the spirit world and are not a part of our soul.  Our soul is our mind or thoughts, our will or violation, and our emotions.

For the most part, we don’t have participation with a vision, it is something that we simply observe, like being a witness of seeing something that is totally separated from ourselves.  A vision is not something we interact with.

However there are realms of visions that are higher up in the scale where we can enter into trances which is experiencing visions of gazing wonder, and we are unconscious when we experience them.  In those type of visions, we do experience ecstasy in our emotions and all of our senses.  However, if we participate in them as in speaking, it is evoked by the Holy Spirit upon our spirits and it is our spirits that respond, using our mouths like when someone is speaking in tongues.  Some who are taken into trances are given the Holy Spirit unction to speak out loud what they are experiencing and/or seeing.

In the highest realms of visions are encountered.  These are when one experiences visitations.  In that level of experience, one can participate with their mind, will, and emotions but under restraints of the great fear and love within the Presence of the Lord.