The difference between a vision and an apparition is that a vision is not an actual manifestation but something that occurs in the mind. An apparition is a physical manifestation of the spiritual object. Generally, a vision is not an actual appearance of something, where an apparition is. However, an actual object that exists spiritually can appear in the form of a vision that is not seen by others. Apparitions, on the other hand, are often seen by more than one person at a time.

• A vision is a “Visual experience of any kind. The term is sometimes used of dreams with no thought of supernatural revelation (see literal renderings of Jb 20:8; cf. 7:14; Is 29:7), but usually refers to the extraordinary religious experience of a prophet.¹Elwell, Walter A., and Barry J. Beitzel. Baker Encyclopedia of the Bible. Grand Rapids, MI: Baker Book House, 1988.
• “In an article for L’Osservatore Romano, Perrella cited Jesuit Father Giandomenico Mucci to explain the difference between a vision and an apparition.  The first is of a spiritual nature, while the second is of a physical one.  That is, the seer has a real and sensible experience of the one in the apparition.”²http://www.catholicnewsagency.com/news/expert_explains_churchs_criteria_for_confirming_marian_apparitions

There are many accounts of visions in the Bible. Here are a few.

• “The vision of Isaiah the son of Amoz concerning Judah and Jerusalem, which he saw during the reigns of Uzziah, Jotham, Ahaz and Hezekiah, kings of Judah,” (Isaiah 1:1).
• “Now it came about in the thirtieth year, on the fifth day of the fourth month, while I was by the river Chebar among the exiles, the heavens were opened and I saw visions of God,” (Ezekiel 1:1).
• “Now there was a disciple at Damascus named Ananias; and the Lord said to him in a vision, “Ananias.” And he said, “Here I am, Lord,” (Acts 9:10).
• “About the ninth hour of the day, he clearly saw in a vision an angel of God who had just come in and said to him, “Cornelius!” (Acts 10:3).
• “A vision appeared to Paul in the night: a man of Macedonia was standing and appealing to him, and saying, “Come over to Macedonia and help us,” (Acts 16:9).

There are occurrences of what could be said to be apparitions.

• “The angel of the Lord appeared to him [Moses] in a blazing fire from the midst of a bush, and he looked, and behold, the bush was burning with fire, yet the bush was not consumed,” (Exodus 3:2).
• “Then Saul said to his servants, “Seek for me a woman who is a medium, that I may go to her and inquire of her.” And his servants said to him, “Behold, there is a woman who is a medium at En-dor. 8 Then Saul disguised himself by putting on other clothes, and went, he and two men with him, and they came to the woman by night; and he said, “Conjure up for me, please, and bring up for me whom I shall name to you…12 When the woman saw Samuel, she cried out with a loud voice; and the woman spoke to Saul, saying, “Why have you deceived me? For you are Saul,” (1 Samuel 28:7-8,12).
• “When the disciples saw Him walking on the sea, they were terrified, and said, “It is a ghost!” And they cried out in fear,” (Matthew 14:26).
• “But when they saw Him walking on the sea, they supposed that it was a ghost, and cried out,” (Mark 6:49).
• “For this very night an angel of the God to whom I belong and whom I serve stood before me,” (Acts 27:23).

There are visions of different things.

• The Lord, “After these things the word of the LORD came to Abram in a vision, saying, ‘Do not fear, Abram, I am a shield to you; Your reward shall be very great,'” (Genesis 15:1).  See also, Genesis 46:2; Numbers 24:4; Isaiah 6:1).
• The Future, ““As for me, Daniel, my spirit was distressed within me, and the visions in my mind kept alarming me. 16 “I approached one of those who were standing by and began asking him the exact meaning of all this. So he told me and made known to me the interpretation of these things: 17 ‘These great beasts, which are four in number, are four kings who will arise from the earth,” (Daniel 7:15-17).
• A man, “A vision appeared to Paul in the night: a man of Macedonia was standing and appealing to him, and saying, “Come over to Macedonia and help us,” (Acts 16:9).
• An angel, “For this very night an angel of the God to whom I belong and whom I serve stood before me,” (Acts 27:23).

Different people have seen visions in the Bible.

• Abraham, After these things the word of the Lord came to Abram in a vision, saying, “Do not fear, Abram, I am a shield to you; Your reward shall be very great,” (Genesis 15:1).
• Jacob, “God spoke to Israel in visions of the night and said, “Jacob, Jacob.” And he said, “Here I am,” (Genesis 46:2).
• Paul, “A vision appeared to Paul in the night: a man of Macedonia was standing and appealing to him, and saying, ‘Come over to Macedonia and help us,'” (Acts 16:9).
• Ananias, “Now there was a disciple at Damascus named Ananias; and the Lord said to him in a vision, “Ananias.” And he said, “Here I am, Lord,” (Acts 9:10).
• Corneilus, “About the ninth hour of the day he clearly saw in a vision an angel of God who had just come in and said to him, “Cornelius!” (Acts 10:3).