Complex sentence: Hostnames may be simple names consisting of a single word or phrase, or they may have appended the name of a Domain Name System (DNS) domain, separated from the host specific label by a period (dot).
Split into simpler sentences: Hostnames may be simple names consisting of a single word or phrase, or they may be structured. On the Internet, hostnames may have appended the name of a Domain Name System (DNS) domain, separated from the host specific label by a period (dot).