The simplest way to understand this as the opposite process of what happened when God created man.

 - Gen 2:7 - Then the LORD God formed man from the dust of the ground and breathed the breath of life into his nostrils, and the man became a living being [literally, "soul"]
 - Zech 12:1 - This is a message from the LORD about Israel: I am the LORD! I stretched out the heavens; I put the earth on its foundations and gave breath to humans.
 - Job 27:3 - as long as I have life within me, the breath of God in my nostrils,
 - Isa 42:5 - This is what God the LORD says— the Creator of the heavens, who stretches them out, who spreads out the earth with all that springs from it, who gives breath to its people, and life to those who walk on it:
 - Ps 104:30 - When you give them your breath, life is created, and you renew the face of the earth.

Note that the first human did not exist without the breath of life.  At death the reverse occurs:

 - Eccl 12:7 - and the dust returns to the earth as it was, and the spirit/breath returns to God who gave it.
 - Ps 146:4 - His breath goes forth, he returns to his earth; In that very day his thoughts perish.
 - Ps 104:29 - When you hide your face, they are terrified; when you take away their breath, they die and return to the dust.

**APPENDIX 1 - רוּחַ (ruach)**

Note that the meaning of the word רוּחַ (ruach) is breath and sometimes spirit as shown by the meaning listed in BDB.

**APPENDIX 2 - Some explanatory notes**

This addition material and update is at the implied request of SRI and Bagpipes.

According to Gen 2:7 a person or human (like all the animals) consist of the  physical body and the breath of life.  We are never told (in the Bible) what this is but without it, a soul cannot exist as documented above.  When a person/soul dies, the soul/person ceases to exist - the body goes into a grave and never returns and the breath of life returns to God who gave it.

At the resurrection, God gives everyone a new "heavenly" body (whatever that means) according to 1 Cor 15:32-49, at least this is true of the righteous.  How the wicked are resurrected is never really stated.

This is as far as we can go because that is all this is revealed.