What is really...I guess real?

The prosses of of having a "dream" but is it really a real dream. How does it happen and why does it happen. Do you think it can happen to you? Well there are many things that can happen to know if it will happen to you,yourself and only you know it's happening....aslo I will be changing the pov like saying I like it's you reading in your pov and you as in like a 3rd person pov