PCM On Non-HD Receiver?

[Damage Inc.]

First off, before I looked more into the technical side of DVDs and BDs,
I didn't know as much about all the different types of audio-formats.
So when I got my first big media-amplifier I was of course able to see
what is on the source I put in the player.
Then I noticed that, as soon as I'd play a CD, the receiver would indicate it's PCM.

Now, I might already think the wrong thing about that.
But first of all, PCM on CDs is lossless right? Or am I already wrong there?
If so, would that mean that I could play the PCM-audio on BD
through my older receiver, even though it's not an HD-receiver, too?
Or is that yet another type of audio/PCM?

Or, I just thought of, it probably can't handle the surround-versions of PCM.
Actually, now I'm confused again, cause you also have audio-DVDs with surround-mixes.
Except, then I don't know if that's Dolby Digital or still PCM...

Confuzementationz...

So, please let me know, I'd like to know how it sticks together.