Humans have been called the animals which make things, and at no time in history has that been so apparent as the present.  Today, every human activity is dependent upon various tools, machines, and systems, from growing food and providing shelter to communication, healthcare, and entertainment.  Some machines, like the tractor, speed up and make more efficient activities that humans have done for hundreds or thousands of years.  Others, such as the airplane or the Internet, make possible things that humans have never been able to do before.  This collection of devices, capabilities, and the knowledge that accompanies them is called technology.