Life, soul, self, person; the vital force animating the body.
Used 105 times in the NT. While Greek philosophical tradition (Plato) taught psychē was inherently immortal and separable from the body, the NT usage is more aligned with the Hebrew nephesh. Jesus uses it in Matt 10:28 ("fear him who can destroy both soul and body in hell") — notably, psychē CAN be destroyed, which contradicts inherent immortality. It often simply means "life" (Matt 16:25-26) or "person" (Acts 2:41, "three thousand souls").
A living being, life, self, person, creature; breath; appetite, desire.
Used over 750 times in the OT. Critically, nephesh does NOT mean "immortal soul" in Hebrew thought. In Genesis 2:7, God breathed into Adam and he BECAME a nephesh (living being) — he did not RECEIVE one. Animals are also called nephesh (Gen 1:20-21). Nephesh can die (Num 23:10, Judg 16:30), be killed (Deut 27:25), and touch dead bodies (Num 6:6). The KJV translates it as "soul" 475 times, "life" 117 times, "person" 30 times, "creature" 9 times — its meaning is determined by context, not by later Greek philosophical categories.