Not really, just that the later cores (Gallatin, Prescott, Cedar Mill) have 775 editions, and the earlier ones (Williamette, Northwood) don't. For specific differences between the architectures, look here: http://en.wikipedia.org/wiki/Pentium_4
Another member posted on here in regards to the subject. He claims that the older P4's don't have pins on the bottom of the CPU but the new LGA775 capable P4's have pins. I never used Intel before which is why I'm confused at this setup. I thought all CPU's have pins on the bottom of them.
Core 2 Duo's don't have the pins on the cpu, and they are LGA775, they have more of little gold pads on the bottom...the pins are in the motherboard...