posted September 10, 2006 02:45 AM
It's just a fancy way of saying how well the planet feels in that particular sign.When a planet is exalted its expression is extra-positive in that sign, almost as if the sign is letting the planet have its fun yet also encouraging it get better and grow in awareness. This is a win-win type of combination.
A planet in detriment is the opposite, it's oppressed and imprisoned in a sign with completely incompatible values. Planets in detriment, especially ones like the moon and mercury can really contribute negatively to the overall personality.
Finally there's the classification of a planet being in fall in a certain sign, but I'm not knowledgeable on what exactly this means.
-jk