ATI Mobility Radeon 9000 On-chip 64MB DDR (128-bit)

...still trying to figure out how notebook graphics work. I ''know'' my Dell desktop has a PCI nVidia graphis card with 64MB RAM. This much I inderstand...

...this I do not understand:

1) What does PCI stand for?

2) What does AGP stand for, how is different from PCI?

3) Is the ATI Mobility Radeon 9000 a ''seperate'' chip on the motherboard of the notebook indepentent of the Intel P4 3Ghz HTT processor?

Thanks for putting up with my lack of product knowlege, my purchasing options are limited by economic factors beyond my control.

For information on the system I am looking at see post: HELP!...I need a CAD Notebook...dated 06/24/2005.