I've read that the soul is made up of the mind, the will (or desire) and emotions.
I think the soul is the unique part of us that makes us human.
We have a body, a soul and a spirit.
People that are unbelievers I guess just have a body and a soul. Or if they have a spirit it's not the holy spirit.
I also heard that animals just have bodies and spirits but no souls.
First mention of soul in the Bible is Genesis 2:7 where it says
And the Lord God formed man out of the dust of the ground, and breathed into his nostrils the breath of life, and man became a living soul.
You know that painting in the Sistine Chapel by Michelangelo called the creation of Adam and its shows Adam, who is lying naked on a treeless rock and God is pointing at him with his finger and it looks like he's giving him an electric shock. Well that isn't even in the Bible so am not sure where that comes from!