2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12850A brief overview is given of the observations of accretion disks in X-ray binaries, discussing their geometry, their effect on the rotation period of the accreting object, their optical and X-ray spectra, time variability, and radio emission and jets. Some outstanding questions for disk theory are listed.12 pp., 5 figs., to be published in Astrophysical Disks, eds. J.Goodman,J.Sellwood, ASP Conf. SerAstrophysicstext