Is this true Dolby Digital?

[BluGamer]

I don't own a receiver yet, so having trouble hooking up a bunch of things (PS3, 360..etc) to my 5.1 speakers. I realized my HDTV accepts a optical cable connection for audio output. So right now, my systems are connected to HDTV through HDMI and sound is playing through optical cable output from HDTV.

Now here's the question. When I insert optical cable directly to my console, it says sound is Dolby Digital. When I use HDTV output, it says "PLII Movie" with a Dolby Digital sign next to it. Is that the same thing? Sound is fine though. I hear it from all 5 speakers accurately, but got a feeling that direct connection to console is better.

Can anyone suggest me what to do?