Galactic winds are ubiquitous in most rapidly star-forming galaxies. They are crucial to the process of galaxy formation and evolution, regulating star formation, shaping the stellar mass function and the mass-metallicity relation, and enriching the intergalactic medium with metals. Although important, the physics of galactic winds is still unclear. Many theoretical mechanisms have been proposed. Winds may be driven by the heating of the interstellar medium by overlapping supernovae explosions, the radiation pressure by continuum absorption and scattering of starlight on dust grains, and so on. The comparison between theory and observation is still incomplete. A full understanding of these issues requires both better theoretical explorations and comparisons with new and existing observations. In this book I discuss the theoretical models of both supernovae driven and radiation pressure driven galactic winds, and compared these models with observations.