The simplest form of technology is the development and use of basic�tools. The�prehistoric�discovery of�how to control fire�and the later�Neolithic Revolutionincreased the available sources of food, and the invention of the�wheel�helped humans to travel in and control their environment. Developments in historic times, including the�printing press, the�telephone, and the�Internet, have lessened physical barriers to�communication�and allowed humans to interact freely on a global scale. The steady progress of�military technologyhas brought�weapons�of ever-increasing destructive power, from�clubs�to�nuclear weapons.