A proxy war is a war between two or more countries. In which a major power on one side is physically fighting.
For Korean War. USA and other allies were fighting North Korea.
While North Korea was backed by USSR. USSR never put troops on the ground, but supplied guns, ammo, and other war materials.
The opposite occurred in Afghanistan in the 1980's.
When USSR was fighting against some Afghanistan troops.
Americans supplied Afghans with guns, weapons, and ammo but did not supply troops.
This was big during the Cold War, and we are still paying for are grandparents errors.