Ok, let's see what we can do with this.
What is a soul? Because it is not physical, I have to go to Bible. In the Bible, the word that is most often translated 'soul' is 'nephesh'. This word is used 757 times in the Hebrew in the Old Testament. It's two most common translations are "life" (129 times), and "soul" (105 times). But as you can see, that is nowhere near the 757 times it is used. Here is an abbreviated list of the other times it is used. For my own sake, I am going to use (ICW) meaning "in conjunction with" other words for the meaning given. Those are the times it is NOT used alone for the meaning given, but is combined with other words. I hope that makes sense. If there is no ICW after the interpretated word, then the word 'nephesh' was standing by itself when interpreted that way -- these times are in bold. In parentheses will be the number of times nephesh is translated as that word
lives, (36)
me, ICW (35)
I, ICW (29)
person, (22)
you, ICW (21)
himself, ICW (18 )
heart (16)
yourselves, ICW (12)
people, (11)
myself, ICW (9)
themselves, ICW (9)
anyone (7)
everyone, ICW (7)
he, ICW (7)
herself, ICW (7)
appetite (6)
creatures (6)
spirit (6)
them, ICW (5)
we, ICW (5)
body (4)
creature (4)
and so it goes. Some of the other translations include man, souls, breath, desire, hearts, needs, and even hunger, mind, and affection!
But I think that gives you an idea. From out studies, we disagree with those translators who chose 'spirit' because of the confusion that causes. We read that the spirit and the soul can be separated, the the use of a sharp knife separating bone and marrow is used as an example. This is in the book of Hebrews.
Essentially, the soul is not uniquely human, but involves the individuality, the desires, the ability to interact with others in ways not necessarily relating to survival, intelligence. Personally, I tend to associate the idea with the concept of 'trainability', which involves the ability to respond in a non-survivalist way with another species or with man.
The soul operates in the body the same way the driver operates in the car. Even when the car falls apart and 'dies' the diver can get out and keep on going. In that case, both are physical entities, but your soul, and mine -- anybody's -- are not physical. Nevertheless, when the body has had it, for whatever reason, the soul 'gets out' and keeps on going.
Death, thus, is NOT unconsciousness and a lack of the body working, but, rather, a separation from the body. We see what happens to the body and so we think of death as the condition of the stopping of the physical processes. It is probably smarter to think of it as separation.
What is the soul made up of? Nothing physical. So I don't know how to answer that.
The soul is exactly what is intelligent, what feels emotions, what makes decisions. It is here the choices are made and the communication which the body translates into speech, is determined. The body is what it acts through.
Thre is a little bit of evidence I can give for this. If a person, whatever a person is, were entirely physical, then we would see less of a person in, perhaps, a double amputee. But we don't. We see a much more intense person, for better or for worse, after something like that. Short of losing your head or trunk, no matter what body part you lose, you do not lose any portion of your individuality or ability to be a person.
I think on the other thread I showed, or at least I hope I did, that the amount of brain present also does not determine the amount of intelligence in a human being. Intelligence and 'personhood' seem to be quite separate from our physical bodies.
The soul does not need the body to 'hold together.' It is separate from the body, but living in it and using it while you are physically alive.
Let's work on this a bit before we try to deal with heaven and hell, OK? You really did ask enough for a book, you know!
Let me add something you did not ask about, though: spirit. It is because we are spiritual beings that humans are made in the image of God, who is Spirit. It is here we are given free will, which our souls so often abuse as expressed through the body. It is the spirit which marks the difference between man and animal. Animals, at least the more complex, have biblical soul, but only man has spirit.