  The measurement of stellar properties such as chemical compositions, masses
and ages, through stellar spectra, is a fundamental problem in astrophysics.
Progress in the understanding, calculation and measurement of atomic properties
and processes relevant to the high-accuracy analysis of F-, G-, and K-type
stellar spectra is reviewed, with particular emphasis on abundance analysis.
This includes fundamental atomic data such as energy levels, wavelengths, and
transition probabilities, as well as processes of photoionisation, collisional
broadening and inelastic collisions. A recurring theme throughout the review is
the interplay between theoretical atomic physics, laboratory measurements, and
astrophysical modelling, all of which contribute to our understanding of atoms
and atomic processes, as well as to modelling stellar spectra.
