1g - first generation eclipse/talon
2g - Second generation eclipse/talon
t25 - 2g's stock turbo (small)
14b - 1g's stock turbo (bigger)
AFC - Air/Fuel Controller (tune leaner or richer)
other stuff:
DSM - Diamond Star Motors (1g/2g eclipse/talon/laser/galant) (joint plant in Normal, Illinois
4G63 - Engine code of the DSM motor in all turbocharged DSMs and the Evo