Diffrence between core 2 dual & dual 2 core processor

Core 2 Duo and dual core?

Core 2 Duo is a trademark of Intel. That's what Intel calls its dual cores with the Core 2 architecture.

Dual core is a generic description of any CPU with 2 processing cores.

Or did you mean Pentium dual core? That's an older generation of Intel dual core processors.
 
the core 2 daul is a newer processor with some enhansment/effeincies improvements - But then I could be all wet, been known to happen on occassions.

One basis is when looking at min requirement for CPU speed for Playing Blu-ray on laptop. - Lower cpu speed for Core 2 dual vs core dual.