Four Geneva Conventions and three Additional Protocols form the core of international humanitarian law
Background
The Geneva Conventions of 1949 and their Additional Protocols are international treaties containing the most important rules limiting the barbarity of war. There are four Geneva Conventions of 1949. They are supplemented by Protocol I and Protocol II, both of 1977, and Protocol III of 2005. They protect people who do not take part in the fighting — civilians, medics and aid workers — and those who can no longer fight, including the wounded, the sick, the shipwrecked and prisoners of war. The Conventions and their Protocols are at the core of international humanitarian law, the body of international law that regulates the conduct of armed conflict and seeks to limit its effects. They contain stringent rules on what are known as grave breaches: those who commit grave breaches must be pursued and tried or extradited, whatever their nationality. The United Nations records that the Additional Protocols were concluded under the auspices of the International Committee of the Red Cross.
In plain words
IHL International humanitarian law — The law that regulates the conduct of armed conflict and seeks to limit its effects.