BGA, PGA, and LGA grid array package reference
BGA: Solder balls on package bottom, permanently soldered to PCB. Best for high-density mobile/embedded. PGA: Pins on package, inserted into socket. User-replaceable (AMD desktop CPUs). LGA: Flat pads on package, pins on socket. Used by Intel desktop CPUs. Higher pin density than PGA.
Grid Array Package is a free online calculator tool. Use it to get instant, accurate results for your electronics calculations.