What we term physical reality is just a particular (perhaps even arbitrary) set of vibrational frequencies that we have agreed upon to provide us with a consistent experience. See What is the basis for the 'vibrational mix' that makes up humanity's current physical reality?

When viewed from that perspective, any dream reality is just as "real" as the physical one, it's just that we have created special body-based vibrational sensors for this physical reality (sight, sound, touch, taste, smell) to give us a more realistic illusion, so the dream realities seem more vague and indistinct in comparison to this one.

But, yes, whatever (or whoever) you create in your dream reality does exist at some frequency level.

But, for most people, unless something is observable by one (or many) of our physical reality sensors (sight, sound, touch, taste, smell), we don't give any credence or value to it...we say it doesn't exist.

But try and convince, for example, a dog that's being deafened by an inaudible (to most humans) dog whistle that the deafening sound doesn't exist just because humans can't hear it :)

Ultimately, your reality is whatever you perceive it to be.

it may be that our dreams
are seeds for what will be
and if universal
it may well be sharred

for one to live the same
moment most likely not,
to experience similar
conceptualizations, yes

There are dreams, visions and premonitions.

If you learn the meaning of these 3 types then you can find an answer to your question.

Dreams are always, emotions playing and acting in symbols in the stage of the night. What we feel in the day time, we might see in images at night. These dreams are bizarre and most of the times meaningless. Sometimes they show us our fears.

Visions, show us exactly in detail, color and precision what will happen in the next day. These dreams have meaning and they are not bizarre. I have experienced this only 3 times in my life yet.

Premonitions are warnings, they have direct connection with divine. A premonition is a friendly guidance from the unseen. Premonitions happen to most faithful and kind people who work with sincere efforts.