A Civil war is a war that is fought between the different groups of the same region or nation, sometimes situation get so intense that takes the form of actual war.

Example: When Sri Lanka recognized Sinhala as the only official language it disregarded Tamils. They felt that they were denied equality. As a result, the relationship between the Sinhala and the Tamils strained and the Sri Lankan Tamils launched movements against the government. This distrust took the shape of Civil war, thousands of people were killed.