Technology is the practical application of scientific discoveries such as electricity and inventions like 3D printers. The document discusses advances in several areas including technology, transport, medicine, communication, and construction over the past 100-200 years. 3D printers can accurately reproduce objects using layers of material, and have applications like producing artificial limbs. Major improvements in transport include cars, trains, and the International Space Station. Medicine has seen life-saving drugs and preventative vaccines as well as organ transplants. Communication technologies have advanced from telephones to smartphones and video calls. Large infrastructure projects now use improved materials and computer-aided design.