What is Nehalem Architecture?

With nehalem architecture Intel introduced 3   variety of processor.  they are core i3 core i5, core i7. there is a quick path interconnect introduced in Neelam architecture who join the separate  cores  and a level 3 cache memory is introduced add sharing with all the core. Buy this architecture Intel can increase the number of course from 2 core to 8 or more depending on the application and the market demand.