The experimental investigation of the QCD phase diagram with heavy ion collisions is an ongoing intense research topic at international accelerator facilities since the 80's and recently got new boost with the first results from the LHC experiments. Together with results from the top RHIC energies they investigate partonic matter in every detail at high temperatures but very low net-baryon densities. Complementary to these studies, the planned Compressed Baryonic Matter (CBM) experiment at FAIR will allow for a detailed investigation of nuclear matter at moderate temperatures but very high net-baryon densities this way completing our knowledge on the phase diagram. In this region of the QCD phase diagram structures such as a first order phase transition between hadronic and partonic matter or further phases such as quarkyonic matter have been predicted. CBM will allow to study these topics with rare probes being sensitive to the medium, i.e. with the measurement of charm production and di-leptons. In this presentation, an overview on the motivation for CBM, its experimental program and status of preparations will be given.