Use of the term " accretion disk " for the protoplanetary disk leads to confusion over the planetary accretion process. The protoplanetary disk is sometimes referred to as an accretion disk, because while the young T Tauri -like protostar is still contracting, gaseous material may still be falling onto it, accreting on its surface from the disk's inner edge. In an accretion disk, there is a net flux of mass from larger radii toward smaller radii.