The Ethernet port is used by connecting your HD24 Ethernet jack to your computer either through a network hub, or directly to a single computer using a crossover type Ethernet network cable (NOT a standard pin-to-pin cable). Your PC must have a 10/100 Base-T network card installed;
most Apple Macintosh computers provide this jack as standard equipment. If you don't have one, any local computer store will have one for about $20.