If it's within 17 minutes of the Sun, it's cazimi.
Basically what happens in cazimi is the planet is considered to be 'sitting in the lap of the king' and is given great power.
If it's further than that, and up to 8-1/2 degrees away, it's combust, even if it's in a different sign.
From 8-1/2 to 15 degrees away it's under the beams, which means it's slightly weakened, but not as much as combustion would weaken it.
In combustion, the planet's power is transferred to the Sun, so will always act in service to the Sun - which is likely to come with one great gift.
Merc/Sun combust is often the sign of a very good writer, for example, but one can get awfully caught up in one's own opinions to the point of not listening to others, Venus combust in Taurus is often the guy who can bed just about any woman but can't establish a permanent relationship, Venus combust in Libra is often a gorgeous woman trapped in a miserable marriage, and so forth.
Jupiter could give wealth, make you a good barrister or a judge, possibly fame, but you might be awfully pompous.
Combust planets for women (any planet) seem to be bad for marriage as a rule, though it doesn't seem to hold true quite so much for men, though it depends on the planet, and I'd definitely still look at it.
A good tutorial on cazimi versus combustion is the Book or Scroll of Ester (which may or may not be in your bible depending on what version you've got). Consider Ester to be cazimi, and a whole lot of other folks in the story combust (even Haman goes combust eventually!). Read in that light you might get a whole new appreciation of biblical literature as well.