Compounds. There are more carbon compounds than there are compounds of all other elements combined. The study of carbon compounds, both natural and synthetic, is called organic chemistry. Plastics, foods, textiles, and many other common substances contain carbon.
backplane is the shared capacity between interfaces on a switch switch fabric is also the shared capacity between interfaces on a switch and can also be the shared capacity between interfaces on multiple switches using some sort of interconnect, typically vendor specific.
Bob does not know to whom the information is going, which is why proxies can be used to protect privacy. In computer networks, a proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers.