had to go get a refreshment
1. I would believe so
2.gddr3 stands for- graphics double data rate- (got this off a review on a site) GDDR-3 graphics memory is the next evolution of high-speed DDR SDRAM technologies that have played a major role in enabling GPUs to drive complex geometries and character animations and deliver visual effects on par with the hottest motion pictures. GDDR-3 graphics memory enables higher memory clock frequencies at a lower power level with fewer components and less constraints on system designers. These technology advances enable NVIDIA partners to bring higher performance solutions to consumers at better prices.
3. AGP is another interface of a video card, there is 3 interfaces that are actually talked about on here... PCI(lowest end) AGP(still being using, but considered old news) and theres PCI-Express x16(cool kids on the block now)
Depending on your motherboard, you'll have a PCI, AGP, or PCI-Ex16 slot for the video card. example, if you have a motherboard with only a AGP slot, you can only use a AGP interface type card on the motherboard, there is still good AGP cards out today, but most would recommend to make the move to pci-e, but AGP is still surviving.
4. Pixel Shader- http://www.nvidia.com/object/feature_pixelshader.html