Observational Constraints.- The First Three Million Years.- Jets from Young Stars: The Need for MHD Collimation and Acceleration Processes.- Star-disk Interaction in Classical T Tauri Stars.- Magneto-Hydrodynamic Models.- to Magneto-Hydrodynamics.- Theory and Models of Standard Accretion Disks.- Theory of MHD Jets and Outflows.- Transit Flows and Jet Asymptotics.- MHD Disc Winds.- Stellar Wind Models.