.cd is the Internet country code top-level domain (ccTLD) for the Democratic Republic of Congo. It was created in 1997 as a replacement for the .zr (Zaire) ccTLD, which was phased out and eventually deleted in 2001.
Except for reserved names like .com.cd, .net.cd, .org.cd and others, any person in the world can register a .cd domain for a fee. The ccTLD is popular (and thus economically valuable) owing to it being an abbreviation for compact disc (other similar ccTLDs are .fm, .am, .tv, .dj, .mu, and .me). Such unconventional uses of TLDs in domain names are known as domain hacks.