A knife is a metal tool with a sharpened metal blade that is used to cut all sorts of things. The plural form of "knife" is "knives." Knives can serve various purposes. Hunters use a hunting knife, soldiers use the combat knife, scouts, campers, and hikers carry a pocketknife; there are kitchen knives for preparing foods, table knives, weapons, knives for throwing or juggling, and knives for religious ceremony or display.
Archaeologists have discovered sharp-edged tools as ancient as 2.6 million years old. Sharp stone tools became more advanced in design during the late Lithic periods, and a variety of techniques was used to produce such ‘knives’ in the Neolithic era. The copper and bronze ages followed, and of course brought tremendous changes to the ‘sharp-edge’ technology. These new metal tools were much more durable than stone ones, and hence mining and metal-processing became an important activity.[1]