Jupiter is the planet of Growth & Expansion. Wherever Jupiter is in your natal chart, is the place where you can expect the theme of evolution and mastery to occur over the course of your life. This part of your life might be blessed, graced and feel like lady luck touches you.
Whatever sign Jupiter is transiting in, will be the place where over the year or so that Jupiter transits it, you will gain the most in knowledge and expansion in your life, albeit, through likely challenges in the area of life ruled by the sign and the the house it is in for you.
Jupiter challenges, unlike Saturn's, are typically easier to overcome, and seem to feel like a revelation or epiphany has happened for you that signals that you have met the challenge and growth has taken place.