PGA

An acronym for Pin Grid Array. This is a type of chip carrier that is usually made out of ceramic or plastic, and has a grid of pins on the bottom which generally plug into a LIF or ZIF socket. PGA carriers tend to be less expensive than slots, so Intel has started using them again for its CPU's: See Socket 370, Socket 7, Socket 8.

Pin Gird Array. A more 'correct' way of saying 'socket'. There are many variations on this theme, most perpetuated by Intel. They include (but not limited to) the Staggered Pin Grid Array (SPGA), Flip-Chip Pin Grid Array (FC-PGA) and Plastic Pin Grid Array (PPGA).

Abbreviation for Professional Graphics Adapter. Sold by IBM at about the same time as EGA and supported a resolution of 640x400 as opposed to EGA's 640x350. Also had a lot of dedicated hardware to shift the graphics processing onto the card rather than the processor.

Cost a fortune and was targetted at CAD applications. The only time I've ever seen one was in a real IBM AT that was used by the head of CDT at my school.