Say John had a cup of coffee that smelled real good and I wanted some. He went ahead and made me a fresh pot made up of the same freshly ground coffee beans he was enjoying. Tastes the same as his, looks the same as his and is just as enjoyable because it's the exact same coffee.
Now, let's say that two months later I met up with John again and wanted the same great coffee we had enjoyed before, once again. The only thing is that [in order to preserve the freshness] he had ground them up and freeze-dried the coffee beans. Yes, it's the same coffee with the same measurements and it's just as fresh, right? It may be the same coffee made the same exact way but there is something different. It looks the same, it may smell the same.....but it just doesn't taste the same. There is just "something" different about it.
The original CD is the fresh ground coffee. The freeze-dried coffee is the burnt/lossless/computer driven copy of the original. One sounds good but the other has this element missing and there's just something different about it.