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.
'ping' is a computer network utility program used to determine the accessability of another computer on a network. Information gathered from the 'ping' program can also show the amount of time it took to contact the other computer thereby establishing if there are network delays between the two systems. The usage of this term probably originated with computer hobbyists or folks working in the computer industry.