The Faint Source Survey (FSS) is the definitive Infrared Astronomical Satellite data set for faint point sources. The FSS was produced by point-source filtering the individual detector data streams and then coadding those data streams using a trimmed-average algorithm. The resulting images, or plates, give the best estimate from the IRAS survey data of the point source flux density at every surveyed point of the sky. The Faint Source Catalog (FSC) is a compilation of the sources extracted from the FSS plates that have met reasonable reliability requirements. Averaged over the whole catalog, the FSC is at least 98.5% reliable at 12 and 25 microns, and ~94% at 60 microns. For comparison, the IRAS Point Source Catalog (PSC) is >99.997% reliable, but the sensitivity of the FSC exceeds that of the PSC by about a factor of 2.5. The FSC contains data for 173,044 point sources in unconfused regions with flux densities typically above 0.2 Jy at 12, 25, and 60 microns, and above 1.0 Jy at 100 microns. The FSS plates are somewhat more sensitive but less reliable than the FSC; typically, only sources with SNR>5-6 in the plates are contained in the FSC. Sources with SNR>3 but which do not meet the reliability requirements of the FSC are catalogued in the Faint Source Reject File (FSR, Cat. II/275). The data products, the processing methods used to produce them, results of an analysis of these products, and cautionary notes are given in the Explanatory Supplement to the IRAS Faint Source Survey (see references in fsc.txt).