whats the difference

hi can you tell me whats the difference between these two 7800GT cards?Memory Clock 1.2 GHzClock rate 375 MHzChipset 7800 GSMemory 256 MBBus Type AGPMemory Type DDR3Memory Bus 256-BitHighlighted Features HDTV readyorGrapics Engine: Geforce 7800GSMemory Size: 256MB DDR IIIMemory Bus: 256bitEngine Clock: 375MhzRAMDAC: 400MhzMax. Resolution: 2048x1536@85HzBus Standard: AGP8X/4XVGA Output: YesTV Tuner: NoTV-out: YesVIVO(Video-in.Video Out): NoDVI: Yes