Matthew 10:28 (ESV)

28 And do not fear those who kill the body but cannot kill the soul. Rather fear him who can destroy both soul and body in hell.

In Scripture your soul often simply refers to you yourself: it is who you are. There is indeed a distinction between soul and body. Your soul is somewhat different from your body. Therefore, if you want to know what your soul is, you have to do a very difficult exercise. Look at yourself, think about yourself, and then think your body away. Extract your body, so to speak, from yourself. Then you are left with your soul. So your soul is yourself, apart from your body. As a soul, you go to heaven through your death. In God’s time, after his return, you will be given back a (new) body (2 Corinthians 5:1–5). It somehow seems simple to say what a soul is, but the more you think through this, the more you find that soul and body are inseparable. Yet they are separable, as this verse teaches. So the best description of the soul seems to be: your soul is yourself, minus your body.