Do they actually write their own stuff? Or, do they have writers? When they do live performances, is each one just about the same? Just wondering, as my obersation is few comedians do it on their own (especially those on tv) , but have a team behind them, to pull if together.

I once saw Joan Rivers live, and was amazed by her jokes, some were of poor taste, but still funny. I later saw her on youtube, where I learned that all her shows were exactly the same - kinda like some musicians, and wrestling.