Stands for "Plastic Pin Grid Array" (not the Pretty People Golfer's Association). PPGA is a type of processor design or "form factor" used by the Intel Celeron processor. The design allows the heat generated by the chip to dissipate more quickly. This enables the processor to use more transistors and run at higher speeds without burning a hole in the side of your computer. If you'd like to know more about PPGA, check out Intel's own documention.