  The Juno mission has revolutionized and challenged our understanding of
Jupiter. As Juno transitioned to its extended mission, we review the major
findings of Jupiter's internal structure relevant to understanding Jupiter's
formation and evolution. Results from Juno's investigation of Jupiter's
interior structure imply that the planet has compositional gradients and is
accordingly non-adiabatic, with a complex internal structure. These new results
imply that current models of Jupiter's formation and evolution require a
revision. In this paper, we discuss potential formation and evolution paths
that can lead to an internal structure model consistent with Juno data, and the
constraints they provide. We note that standard core accretion formation
models, including the heavy-element enrichment during planetary growth is
consistent with an interior that is inhomogeneous with composition gradients in
its deep interior. However, such formation models typically predict that this
region, which could be interpreted as a primordial dilute core, is confined to
about 10% of Jupiter's total mass. In contrast, structure models that fit Juno
data imply that this region contains 30% of the mass or more. One way to
explain the origin of this extended region is by invoking a relatively long
(about 2 Myrs) formation phase where the growing planet accretes gas and
planetesimals delaying the runaway gas accretion. Alternatively, Jupiter's
fuzzy core could be a result of a giant impact or convection post-formation.
These novel scenarios require somewhat special and specific conditions. Clarity
on the plausibility of such conditions could come from future high-resolution
observations of planet-forming regions around other stars, from the observed
and modeled architectures of extrasolar systems with giant planets, and future
Juno data obtained during its extended mission.
