Each Internet site is located on a server. A server is basically a computer hooked up to the Internet, or internet. This hook up can be by ethernet, or by modem. Sometimes it uses a T1 link. Which in all sense, is optical fiber.
Optical fiber is very fast.
A device used to transmit and receive digital data over normally analog communications lines, usually as an audio signal on telephone circuits. The rate of data transfer can be increased using data compression. Wireless modems send or receive data as a radio signal. Also, the folder name on 199.17.198.6's server. It can also be a htm.