Diphtheria (dif-THEER-e-uh) is an infection of the lining of the upper respiratory tract (the nose and throat). It is a serious disease that can cause breathing difficulty and other complications, including death.
The Internet is not synonymous with World Wide Web. The Internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet.
The Internet is the communications network that lies behind your computer and connects you to the outside world. In the beginning, it was a few computers connected together in one building and swapping text messages. Now there are millions of computers connected around the world using fibre optic cables and satellite links to transfer digital information - text, sound and video.