I am sure everyone will have their own definition but for me straight up rock is more simple; driven guitar, bass and drum driven
If there are keyboards they are supporting and "filling out" the guitars
The lyric themes tend to be a bit more simple and direct
"Prog Rock" to me is a bit more "folky" with more "complex" melodies,
To me (and this is purely a personal opinion as I don't like this genre) I find prog rock a bit pretentious - like it is trying to make "rock music" more "sophisticated"
I like my rock on the "blusier" side of the tracks
I used to feel this way about folk music - but my tastes have changed since listening to the excellent folk songs on this forum
Perhaps the same will happen with "prog rock" but it doesn't do anything for me at the moment - even the "greats" - so don't take it personally
I noticed you mentioned in the thread on your song that you don't like how music is "pigeon holed"
I must personally disagree as I think it can be really good to stick to a "genre" and use the "tricks of the trade" that have come before and give them a new twist, rather than trying to re-invent the wheel
To be fair though, I am coming from the "pitching" angle where it is better to clearly define a genre to work in