Redshift:The shift of the observed wavelength of light from a distant object towards longer, redder wavelengths, caused by the expansion of the Universe or the motion of the object away from the observer.
Large-Scale Structure:The distribution of matter in the Universe on the largest scales, including galaxies, galaxy clusters, and filaments, which are shaped by the underlying gravitational field.
Spectroscopy:The study of the absorption and emission of light by matter, used to determine the chemical composition, physical properties, and motion of astronomical objects.