Complex sentence: Civil marriage, which does not exist in some countries, is marriage without religious content carried out by a government institution in accordance with the marriage laws of the jurisdiction, and recognised as creating the rights and obligations intrinsic to matrimony.
Split into simpler sentences: Civil marriage, which does not exist in some countries. In some countries, a marriage without religious content carried out by a government institution in accordance with marriage laws of the jurisdiction, and recognised as creating the rights and obligations intrinsic to matrimony.