The main difference between Homo sapiens (modern humans) and Neanderthals lies in their anatomy. Neanderthals had several distinct physical features that set them apart. They typically had a stockier and stronger build, with a larger bone structure and shorter limbs. Neanderthals also had a prominent brow ridge, a larger and more robust face, and a larger nose compared to Homo sapiens. Additionally, Neanderthals had a different brain shape and size, with specific variations in their skull structure.
