A soul is simply another word for an individual person, whether that person is a living soul or became a dead soul. The spirit is the breath of life. At death, this life-sustaining breath is returned to Almighty God. God created Adam from the dust of the earth. He then received the breath of life in his nostrils, and he then became a living soul. Adam did not receive a soul, instead he became one. Animals are souls also.  A soul has it's own personality that characterizes that individual from others. If a soul or individual chooses to live a life that is in opposition to God's words, that soul will die. Those who choose to follow God's words will exist forever in a perfect world of peace, happiness, and righteousness.

Spirit of Life

Job 27:3-4  Job credits God for giving him breath in his nostrils.

Ecclesiastes 12:7  At death, the spirit (breath) returns to God who gave it.

Soul

Genesis 2:7  Man was created from dust, given the breath of life in his nostrils, and became a living soul.

Ezekiel 18:4, 20  All souls belong to Jehovah God. The soul that sins will die, unless they repent.

Revelation 16:3  All souls or individual creatures, in the sea will die. This proves that animals are souls too. 

Acts 3:22-23  Souls who don't listen will be destroyed.

If you enjoyed this study, you may also be interested in the study topic titled: What is Hell?

Additional references for further study:

Genesis 7:21-23
1 Peter 3:20
Joshua 11:11
Hebrews 4:12
Matthew 16:25-26