Solar radio emissions

In this paper, we present a tutorial review which was presented at the first Advanced School on Space Environment (ASSE 2004). We first describe the basics of radioastronomy definitions, and discuss radiation processes relevant to solar radio emissions like plasma emission, free-free bremsstrählung and gyromagnetic emissions. We illustrate these fundamentals by describing recent solar radio observations and the constraints they bring on different solar physical parameters. We focus on solar radio emissions from the quiet sun, active regions and during explosive events known as solar flares, and how the latter can bring quantitative informations on the particles responsible for the emission. Finally, particular attention is paid to new radio diagnostics obtained at very high frequencies in the millimeter/submillimeter range, as well as to radio emissions relevant to Space Weather studies.