This paper reviews the main scientific goal of the DARWIN
experiment: the 40 ton dual-phase Xenon TPC for WIMP dark matter
search.
Dark matter experiments with target masses beyond the ton
scale are already reality: the XENONnT detector is currently taking
its first science run data. DARWIN will reach
spin-independent WIMP-nucleon scattering cross section values of a few
10$^{-49}$ cm$^2$, where coherent neutrino interactions with atomic
nuclei become the dominating and irreducible background. In this
paper the other important science channels that can be explored by
DARWIN are discussed, including solar neutrinos, axion and
axion-like particles, supernova neutrinos and neutrinoless
double-beta decay of $^{136}$Xe.