Comparison with artificial galaxy models is essential for translating the
incomplete and low signal-to-noise data we can obtain on astrophysical stellar
populations to physical interpretations which describe their composition,
physical properties, histories and internal conditions. In particular, this is
true for distant galaxies, whose unresolved light embeds clues to their
formation and evolution as well as their impact on their wider environs.
Stellar population synthesis models are now used as the foundation of analysis
at all redshifts, but are not without their problems. Here we review the use of
stellar population synthesis models, with a focus on applications in the
distant Universe.Comment: 32 page review, published in Galaxies special issue, "Star Formation
in the UV", ed. Jorick Vin