The usual answer is that while dreaming, you're reliving the events of the day, while your subconscious forms associations and decides what you ought to remember and can safely forget.
Those dreams that you do remember can seem jumbled because your conscious mind is not often privy to what your subconscious is doing, nor how it likes to organize your thoughts and memories.
when they are dreaming
Not dreaming can be a sign of sleep deprivation or a sleep disorder, such as REM sleep behavior disorder. It may also indicate poor quality sleep, leading to cognitive and emotional disturbances. Dreaming is thought to play a role in memory consolidation and emotional processing, so not dreaming may affect these functions.
You move in your sleep according to what you're dreaming about
REM
They are dreaming
Yes ;)
It's sleep talk/laugh. Some people just tend to be really connective while dreaming.
Yes, when you enter REM sleep, (REM= rapid eye movement), this is when you are dreaming, your eyes move just as if you were looking at what you are dreaming about
No because you daydream with your eyes open and sleep with your eyes closed
True.
by closing its eyes and dreaming :)
Not dreaming during sleep could mean they are in deep sleep stages where dreaming is less likely to occur, or they simply do not remember their dreams upon waking. It is also possible that they have a sleep disorder affecting their REM sleep, which is when most dreaming occurs.