Photometric redshifts refer to the measurement of an object's redshift (or the stretching of light waves towards longer, redder wavelengths) using only the object's observed flux in various photometric bands (i.e., measurements of light intensity at different wavelengths). This technique is commonly used in astronomy and astrophysics to estimate the distances and ages of galaxies, as well as to study the evolution of the universe. Photometric redshifts are typically less accurate than spectroscopic redshifts, which require detailed analysis of an object's spectrum, but they are much more efficient for large-scale studies of numerous objects.