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.
Historically, networking has been performed through two abstractions, a Data plane and a Control plane. The data plane rapidly processes packets: it looks at the state and packet header, then makes a forwarding decision. The control plane is what puts that forwarding state there.