How does the exploration of a Solar System body differ fundamentally from that of an exoplanet?

Answer

Solar System exploration uses direct in-situ measurement; exoplanet exploration relies on inference from light measurements.

Exploring neighbors within our Solar System involves direct measurements of surface conditions and immediate atmosphere, whereas exploring exoplanets relies on remote sensing techniques like light curves and spectroscopy to infer properties.

How does the exploration of a Solar System body differ fundamentally from that of an exoplanet?
NASAexplorationplanets