  Supernovae release an enormous amount of energy into the interstellar medium.
Their remnants can observationally be traced up to several ten-thousand years.
So far more than 230 Galactic supernova remnants (SNRs) have been identified in
the radio range. Detailed studies of the different types of SNRs give insight
into the interaction of the blast wave with the interstellar medium. Shock
accelerated particles are observed, but also neutron stars left from the
supernova explosion make their contribution. X-ray observations in conjunction
with radio data constrain models of supernova evolution.
  A brief review of the origin and evolution of SNRs is given, which are
compared with supernova statistics and observational limitations. In addition
the morphology and characteristics of the different types of SNRs are
described, including some recent results and illustrated by SNRs images mostly
obtained with the Effelsberg 100-m telescope.
