In Proverbs we learn it’s divine inspiration teaching us how to live practically for an effective life. Fear of the Lord is true knowledge, wisdom, and discipline.
In Ecclesiastes we learn that it’s earthly experiences, from a human point of view, not divine. Everything on this earth is vanity (emptiness) apart from God.
In Song of Solomon we learn that it’s a love poem. A union between man and woman in marriage as in the relationship with Christ and His people.