What determines a graphic card speed?

Question

Also, What type of slots are there. I heard it was AGP, PCI+ and another, can you tell me what they stand for?

Answer 1

A lot of things:

Clock speed of the processing unit (core speed)
# of pixel processing units onboard (i.e. # of pipelines)
memory type onboard (DRAM? VRAM? DDR2 GRAM? GRAM? DDR3?)
memory interface size (64-bit? 128-bit? 256-bit? Larger?)
memory clock speed (memory speed)
pixel processing efficiency (this one is not a numerical measurement)

AGP, PCI, and PCI-Express are the slots.

PCI = Peripheral Component Interconnect, a standard pushed by Intel to replace the older ISA but and its successors, VLB, EISA, and MicroChannel.

AGP = Accelerated / Advanced Graphics Port, better than PCI, basically. Available from X1 to X8.

PCI-Express, even faster than AGP, replaces PCI, available from X1 to X16 (for video cards).