The acronym USSR stands for the Union of Soviet Socialist Republics. It was a federation of multiple socialist republics, established in 1922 and existing until 1991, covering a vast area across northern Eurasia from the Baltic Sea to the Pacific Ocean

. The USSR was the world's largest country by area and was founded on communist ideology, aiming to unite various republics under a socialist government

. The name reflects its political structure rather than a geographic entity, emphasizing the union of socialist republics