  This paper gives an overview of TEMPLATES, a JWST Early Release Science
program that targeted four extremely bright, gravitationally lensed galaxies:
two extremely dusty, two with low attenuation, as templates for galaxy
evolution studies with JWST. TEMPLATES obtains a common set of spectral
diagnostics for these 1.3 < z < 4.2 galaxies, in particular H alpha, Paschen
alpha, and the rest-frame optical and near-infrared continua. In addition, two
of the four targets have JWST coverage of [O III] 5007 Angstrom and H beta; the
other two targets have have JWST coverage of PAH 3.3 micron and complementary
ALMA data covering the [C II] 158 micron emission line. The science goals of
TEMPLATES are to demonstrate attenuation-robust diagnostics of star formation,
map the distribution of star formation, compare the young and old stellar
populations, and measure the physical conditions of star formation and their
spatial variation across the galaxies. In addition, TEMPLATES has technical
goals to establish best practices for the Integral Field Units (IFU) within the
NIRSpec and MIRI instruments, both in terms of observing strategy and in terms
of data reduction. The paper describes TEMPLATES's observing program,
scientific and technical goals, data reduction methods, and deliverables,
including high-level data products and data reduction cookbooks.
