  A simple introduction to physics of CMBR polarization and the Faraday
rotation of the latter in cosmic magnetic field is presented. The content of
the lecture is the following: 1. Description of polarization of photons. 2.
Polarization field of CMBR. 3. Faraday effect. 4. Cosmic magnetic fields. 5.
Faraday rotation of CMBR polarization.
