This will probably get closed but I can say that powder heroin smokes thickly and can often taste like crap. Black tar heroin smokes but not so much as powder and tastes heavenly...like opium.
i would love to smoke some of that black tar. I have yet to get my hands on some seeing as I live in Detroit. All we get is powder, although i am NOT complaining!!
Basically it's less refined. Somebody with chem knowledge can add more...but the weird thing is, even though black tar tastes like raw opium, it still has that vinegary acetic anhydride taste / smell...even moreso than powder. You'd think black tar would taste less acetylated because it's more "crude"...but I dunno...