Copper core conduction works the same way as aluminum heat conduction. Certain types of metals are more efficient at transferring heat from a hot spot to a cold spot. It’s just that copper is a little more efficient at this than aluminum due to its molecular structure.
Copper core cookware uses a single layer of copper to cause more even heating across a cooking surface. The copper layer absorbs heat and radiates it to the aluminum and stainless steel layers, too. Because it radiates heat so well, it doesn’t stay hot for very long either.