AGP (Accelerated Graphics Port)

Short for Accelerated Graphics Port, AGP is an advanced port designed for Video cards and 3D accelerators. Designed by Intel and introduced in August of 1997, AGP introduces a dedicated point-to-point channel that allows the graphics controller direct access the system memory. 

AGP is gaming interface, only video card were made for it. AGP is most of the time brown in color and sometimes maroon. AGP more powerfull than PCI, ISA, EISA, Vesta local bus, and MCA when it comes to gaming power. There are many type so know the pinout on the AGP slot on motherboard, the motherboard specs should say something like AGP 4x ect...

The type of AGP:

AGP 1x
AGP 2x
AGP 4x
AGP 8x
AGP Pro
AGP 64 bit

And stuff base off of AGP
AGI
AGX
XGP

You can go to wikipedia.org to find the pinouts.

AGP is being phased out by PCI-Express. AGP video card are still usefull, the newer AGP video cards can handle the new pc games. In a few more years there will be no more company making motherboard with AGP slots on them.