Knives have been used as tools, weapons, and eating utensils since the beginning of the human timeline. Knives started out being made of stone, attached to some kind of handle. Further along the human timeline came flint--- a type of rock that can be flaked by striking it with another rock until the edge becomes as sharp as a scalpel. In fact, some surgeons prefer to use scalpels made from flint. Then, as bronze, iron, copper, and steel were discovered, knives were designed with those components in the blade. But, no matter what the knife has historically been made of, for the most part, it was one knife that served all purposes.
As time and human sophistication evolved, so did knives. Now, there are knives that are designed for specific uses, and finding the best knife brands depends on the intended purpose. Humans went from a knife to knives.