One of the most complex and often mistranslated words in Hebrew. Nephesh does NOT mean an immaterial soul separate from the body (as in Greek philosophy). It refers to the whole living being — a person as a breathing, desiring, feeling creature. Genesis 2:7 says Adam "became a living nephesh" — not that he received one.
When the Psalms say "my nephesh thirsts for God," they mean the whole person yearning for God. Hebrew anthropology is holistic: a nephesh is not a ghost trapped in a body but a unified, embodied being. This has enormous implications for understanding death, resurrection, and the afterlife.
The translation of nephesh as "soul" has imported Greek dualistic thinking into Hebrew texts. The biblical hope is not the escape of souls to heaven but the resurrection of whole persons. The Greek psychē (G5590) inherits some of this complexity.