Or so Adam Warner describes them. Well, they are pesky when options snatch money from you and you haven't a clue how it happened. I spent quite some time bewildered like that. lol
Anyway, Adam has committed to offer up some explanations over the coming week, starting with vega. I always think it's good to go over these definitions numerous times from different writers, you often pick up a new and useful concept.
Keep an eye out for the other greeks as they come on line.