Advection-dominated accretion is a self-similar solution where viscous energy is stored as entropy rather than radiated. This occurs when optical depth is either very small or very large. The solution shows the gas rotates sub-Keplerian, leading to slow spin rates of accreting stars. The Bernoulli parameter is positive, suggesting outflows and jets. Convection may enhance these effects. Advection-dominated accretion explains slow spin rates and outflows in accreting systems. The self-similar solution has properties like sub-Keplerian rotation, high sound speed, and convective instability. The Bernoulli parameter is positive, allowing outflows. Advection-dominated flows are common in various astrophysical systems, including cataclysmic variables, young stellar objects, and accreting neutron stars and black holes. The solutions suggest that advection-dominated flows may be more common than previously thought, with implications for accretion rates and outflows. The results are relevant for understanding accretion in astrophysical systems.Advection-dominated accretion is a self-similar solution where viscous energy is stored as entropy rather than radiated. This occurs when optical depth is either very small or very large. The solution shows the gas rotates sub-Keplerian, leading to slow spin rates of accreting stars. The Bernoulli parameter is positive, suggesting outflows and jets. Convection may enhance these effects. Advection-dominated accretion explains slow spin rates and outflows in accreting systems. The self-similar solution has properties like sub-Keplerian rotation, high sound speed, and convective instability. The Bernoulli parameter is positive, allowing outflows. Advection-dominated flows are common in various astrophysical systems, including cataclysmic variables, young stellar objects, and accreting neutron stars and black holes. The solutions suggest that advection-dominated flows may be more common than previously thought, with implications for accretion rates and outflows. The results are relevant for understanding accretion in astrophysical systems.