Jupiter represents growth, expansion, freedom, opportunities, self-development, long term plans and aspirations, etc.
Transiting Jupiter conjuncts natal Jupiter i.e. Jupiter return about every 12 years. That means there’s a double dosage, a double whammy of Jupiter during such a time. Indeed, there’s often a growth surge during Jupiter return at about 12, 24, 36, 48, 60, 72 and so on years old.
How we experience growth will be determined by our natal chart. But it can be very helpful to cast a Jupiter return chart to see where the focus of growth might be located and what may support or get in the way of growth, not unlike a solar return. If you haven’t cast a Jupiter return chart, go on and give it a go. It can be rather instructive!