In addition to the detailed explanation given by Our Player No.1# woodpusher,I'm dead sure ,that re-playing Sicilian Najdorf games;with BLACK pieces,as played by Our EVERLASTING R.J.FISHER;from chess database games:B90,B92,B93,B97,B99.Again playing with White pieces:B32,B44,B88,B90,FINALLY,smashing the Sicilian Dragon:B35,B36,B75,B76,B77,it will greatly help all friends,zanboryaa

I believe the Najdorf is more theoretically sound than the Dragon (it is more popular in GM circles), While the Dragon may provide more tactical chances for Black to win in typical class tournament or club play, where players don't know all of the lines and can't consult books or databases.  The main downside of the Dragon, IMHO, is the hook for White's attack, the Black g pawn.

White's pawn storming on the Kingside "gets there" a move earlier than when the g pawn has stayed home.  This makes it even more critical that Black not waste any time with his counter play.  Still, the Dragon remains quite popular among aggressive players at every level.