[en] A brief summary is given of the physics of the problem of laser-mater interaction. In the limit of very low intensities, the absorption is dominated by inverse bremsstrahlung. At higher intensities and in a homogeneous medium, there are several parametric processes that may become significant. The threshold intensities for the onset of several parametric instabilities are listed. Results for threshold intensities and growth rates just above threshold are briefly discussed for an inhomogeneous plasma. A brief description of resonance absorption in an inhomogeneous plasma is included. (author)