It isn't quite that simple unfortunately. Intel for some reason have decided to make their product range complicated.

Celeron - Could be anything from a Pentium 2 based chip up to the latest Core 2 series. Always single core however.
Pentium D - Two Pentium 4 based cores. Not made any more.
Core - Original Core architecture - Comes in Solo and Duo variants
Core 2 - 2nd generation Core architecture - Comes in Solo, Duo, Quad (Only desktop at the moment) and Extreme variants
Pentium Dual Core - Low end Core 2 CPUs

If it doesn't specifically say "Core 2 Duo" then assume that its either a lower/older model or that it isn't Intel. The latest and greatest currently is Core 2 Duo/Extreme.