I know this post is old, but in case anybody reads it, I'd thought I'd put in my 2 cents.
I do know a ton about semiconductors as I have a degree in Microelectronic Engineering. The difference between ICs that you all are talking about is only in application. In real life there are only two types of transistors used to make up integrated circuits as of now. Bipolar Junction Transistors and the MOSFET are the two primary transistors that you wire together to form an integrated circuit such as an amplifier or anything else.
When talking about processors and all that fun stuff, you have to realize that newer processors are cramming more transistors into a small piece of silicon and therefore change the line widths that they are printing. Intel just moved to 45 nm which is the gate channel length between the source and the drain of a transistor. Now, they can put 700+ million transistors into a small piece of silicon.
If you have any other questions about semiconductors, send me a message and we can talk about it.