Solar radio emissions represent a clear evidence of far-reaching effects of solar eruptions injecting energetic electrons into the Interplanetary (IP) medium. Kinetic energy of these electrons are partly converted into electromagnetic radiation via the plasma emission mechanism that depends on the properties of the ambient medium. Therefore solar radio emissions provide us with an important diagnostic tool for remote measurements of the electron density and magnetic field topology in the inner heliosphere. Type III radio bursts are consequence of impulsively accelerated electrons associated with solar flares. Type II radio bursts are generated by suprathermal electrons accelerated on IP shock fronts of propagating CMEs by the plasma emission process similar to type III radio bursts. Type II radio bursts are valuable precursors of CME arrivals, which may trigger severe geomagnetic storms if they are Earth-directed.