The paper presents a method for interpreting faint galaxy data by focusing on the integrated light from the galaxy population. It models the emission history of the universe at ultraviolet, optical, and near-infrared wavelengths from the present epoch to z ≈ 4, using deep spectroscopic samples and the Hubble Deep Field (HDF) imaging survey. The study finds that a simple stellar evolution model with a time-dependent star formation rate (SFR) and a universal initial mass function (IMF) can well fit the global spectrophotometric properties of field galaxies. While both a Salpeter IMF with some dust reddening and a steeper mass function can reproduce the data, a Scalo IMF produces too much long-wavelength light and fails to match observed galaxy colors. The best-fit models show a sharp rise in SFR from z = 0 to a peak at z ≈ 1.5, followed by a decline at higher redshifts. The stellar mass density at the present epoch is found to be Ω_s h_50² ≳ 0.005, consistent with observed values in nearby galaxies. The models account for the entire background light recorded in galaxy counts down to the faintest magnitudes probed by the HDF. Only ~20% of the current stellar content is produced at z > 2, suggesting a low cosmic metallicity at early times, consistent with the enrichment history of damped Lyman-α systems. The biggest uncertainty is the poorly constrained amount of starlight absorbed by dust and reradiated in the infrared at early epochs. A "monolithic collapse" model, where half of the present-day stars formed at z > 2.5 and were shrouded by dust, can be consistent with the global history of light but overpredicts the metal mass density at high redshifts as sampled by QSO absorbers. The study also discusses the implications for galaxy formation and evolution, including the star formation history, stellar mass density, and metal production. The results suggest that the majority of stellar mass was assembled between z ≈ 1 and z ≈ 2, and that the observed colors of high-redshift galaxies indicate some amount of dust extinction. The models are consistent with the observed extragalactic background light and the cosmic infrared background, but overproduction of infrared light could occur in scenarios with significant hidden star formation. The study concludes that the universal IMF is likely Salpeter, and that the metal production history is consistent with observations of damped Lyman-α systems.The paper presents a method for interpreting faint galaxy data by focusing on the integrated light from the galaxy population. It models the emission history of the universe at ultraviolet, optical, and near-infrared wavelengths from the present epoch to z ≈ 4, using deep spectroscopic samples and the Hubble Deep Field (HDF) imaging survey. The study finds that a simple stellar evolution model with a time-dependent star formation rate (SFR) and a universal initial mass function (IMF) can well fit the global spectrophotometric properties of field galaxies. While both a Salpeter IMF with some dust reddening and a steeper mass function can reproduce the data, a Scalo IMF produces too much long-wavelength light and fails to match observed galaxy colors. The best-fit models show a sharp rise in SFR from z = 0 to a peak at z ≈ 1.5, followed by a decline at higher redshifts. The stellar mass density at the present epoch is found to be Ω_s h_50² ≳ 0.005, consistent with observed values in nearby galaxies. The models account for the entire background light recorded in galaxy counts down to the faintest magnitudes probed by the HDF. Only ~20% of the current stellar content is produced at z > 2, suggesting a low cosmic metallicity at early times, consistent with the enrichment history of damped Lyman-α systems. The biggest uncertainty is the poorly constrained amount of starlight absorbed by dust and reradiated in the infrared at early epochs. A "monolithic collapse" model, where half of the present-day stars formed at z > 2.5 and were shrouded by dust, can be consistent with the global history of light but overpredicts the metal mass density at high redshifts as sampled by QSO absorbers. The study also discusses the implications for galaxy formation and evolution, including the star formation history, stellar mass density, and metal production. The results suggest that the majority of stellar mass was assembled between z ≈ 1 and z ≈ 2, and that the observed colors of high-redshift galaxies indicate some amount of dust extinction. The models are consistent with the observed extragalactic background light and the cosmic infrared background, but overproduction of infrared light could occur in scenarios with significant hidden star formation. The study concludes that the universal IMF is likely Salpeter, and that the metal production history is consistent with observations of damped Lyman-α systems.