What does the 38th parallel do

Hello!

so this is all i have read.

The 38th parallel north is a circle of latitude that is 38 degrees north of the equatorial plane of the Earth. (Crosses Europe, the Mediterranean Sea, Asia, the Pacific Ocean, North America and the Atlantic Ocean) Parallel 38, delimits approximately North Korea and South Korea. The line was chosen by the U. S. military near the end of World War II as the army's border, north of which the USSR was to accept the surrender of Japanese forces in Korea and south of which the Americans were to accept the surrender of the Japanese.

Separate North Korea & South Korea after WWII