What is a simultaneous dream?

I believe there are 3 meanings. For the sake of argument, let's say :

Simultaneous Dream ~ having 2 dreams at the same time; dreaming 2 dreams at once; 2 people having the same dream at the same time or different times. 

I'm sure I've experienced 2 of the 3. I've had 2 dreams at the same time. In this instance, I refer to a dream as something we wish to have or achieve. I once wanted to be a stage actress and the (just happens to be
female) lead guitarist in a hardcore rock band. I have
been these things alone in my living room but never at
the same time.

I'm trying to remember if I have dreamed 2 dreams at the same time while sleeping. Of course, they would be lucid
dreams which will probably be a different post one day.

Finally, yes, I have had the exact same dream at the exact same time (while sleeping) as several people whom I've been very close to in life. Hmmmm, more ideas for posting.

I guess I should have started with something more simple. Why didn't I? "Deja Vu" was not available.