HTTP (HyperText Transfer Protocol) is the underlying protocol used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. In other words, HTTP is the set of rules for exchanging files.

For example, when you enter a URL like www.sena.com in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page www.sena.com. Web browsers typically default to the HTTP protocol. For example, typing www.sena.com is the same as typing http://www.sena.com. For more information, please refer to this page
http://www.networksorcery.com/enp/protocol/http.htm.

In data communications, a hub is a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions.