What is meant by a proxy war and how does this term apply the the Spanish Civil War

Sorry I only know one of these answers...A proxy war is a war fought between groups or smaller countries that each represent the interests of other larger powers, and may have help and support from

Explanation:

A proxy war is a war in which major powers become involved but do not declare war on one another. During the Spanish Civil War, both Germany and the Soviet Union took sides and became actively involved, but they did not formally declare war on one another.