Can PS3 play standard DVDs

Yes and if you have a HD TV they are upscaled to HD and look great.

The PS3 also will play DVDs that you burn on Your Media Center computer of TV shows you recorded. It has played everything much better than in my Sony DVD/VCR combo player so that I no longer even consider using it to play DVDs. Of course it also Plays Blu Ray discs and the pictures look better than the 720P HD broadcast of the same movie.