Now this might sound like too many previous questions, but I am really confused about these terms. I was trying to understand how "dual core" is different from "Core 2 Duo", and I came across some answers. For example, this answer states:

Core 2 Duo has two cores inside a single physical package

and

dual core is 2 cpu in a package 2 cpu's in a die = 2 cpu's made together 2 cpu's in package = 2 cpu's on small board or linked in some way

Now, is a core different from a CPU? What I understand is there is something that does all the heavy computation, decision making, math and other stuff (aka "processing") is called a CPU. Now what is a Core? And what is a processor when somebody says he has got a Core 2 Duo? And in this context what is a Package and what is a Die?

I still don't understand the difference between Core 2 Duo and Dual Core. And can somebody explain hyper-threading (symmetric multi-threading) too if they are super generous?