Dual core and quad core mean having effectively 2 and four processors in your computer respectively. Fairly recent advances meant that it was possible, faster and of course cheaper to put independent cores on the one physical chip rather than have multiple [processors as such, for which their was a brief trend. I think it still holds true that laptops cant currently support more than dual core technology, probably because of heat issues, though that's a guess. The modern equivalent of Pentium 4, once Intel's flagship chip (flagchip?) is the iCorex series, i think the iCore3 is the top one, then 5 then 7; I think there may be a couple of chips with the Pentium brand still hanging around. But there are other processor manufacturers out there who have long since closed the gap, AMD being probably the most famous. Did any of that make any sense?