Dream of/Dream about

[Arara]

In the dictionary I have found :
To experience a dream in sleep: dreamed of meeting an old friend.
In an other book I have read
Last night I dreamed about being alone on desert island.

Which one is correct dream about or dream of when i talk about dream in sleep?

I remember somebody told me that dream of is more comun to be used in day dream, does it make sense?

[Allen165]

In the dictionary I have found :
To experience a dream in sleep: dreamed of meeting an old friend.
In an other book I have read
Last night I dreamed about being alone on desert island.

Which one is correct dream about or dream of when i talk about dream in sleep?

I remember somebody told me that dream of is more comun to be used in day dream, does it make sense?

NOT A TEACHER.

Both are correct. "Of" sounds a tad more formal to me than "about."