What is the difference between a spear and a harpoon?

The spear appeared in the primitive world earlier. The Cro-Magnons have learned to make it out of sharpened stone plates and sturdy wooden foundations. With the help of a spear, they could hunt large land animals. They used it both at close and long distances. The harpoon worked on the same principle, but served for the extraction of aquatic animals. It was invented by primitive people much later. The sharp part of the harpoon has been changed to fit comfortably on the victim’s body. The harpoon had several protrusions.