How do you explain GANGSTA rap to kids?

I'm watching this Doc on VH1 about NWA.  I remember vividly when they came out and how the whole culture of hip hop changed from then on. People were screaming and yelling about what they were saying, but when I listened to them I thought they were amazing writers. Yeah the content was about ghetto life. But what's the difference b/t that and an Iceberg Slim novel? Granted Slim was just as hated but I digress.

Gangsta rap is a huge part of hip hop but not the most uplifting or positive thing. What would you say to a kid that asked you what it was? Would you explain it differently to a boy verses a girl?

What if a kid came to you because you were an old head and could give them the real? Who would you say was the most compelling to the genre?

Do you think that GR is still relevant today, or has it morphed for the better or worse?