South Korea, country in East Asia. It occupies the southern portion of the Korean peninsula. The country is bordered by the Democratic People’s Republic of Korea (North Korea) to the north, the East Sea (Sea of Japan) to the east, the East China Sea to the south, and the Yellow Sea to the west; to the southeast it is separated from the Japanese island of Tsushima by the Korea Strait. South Korea makes up about 45 percent of the peninsula’s land area. The capital is Seoul. South Korea faces North Korea across a demilitarized zone (DMZ) 2.5 miles (4 km) wide that was established by the terms of the 1953 armistice that ended fighting in the Korean War (1950–53). The DMZ, which runs for about 150 miles (240 km), constitutes the 1953 military cease-fire line and roughly follows latitude 38° N (the 38th parallel) from the mouth of the Han River on the west coast of the Korean peninsula to a little south of the North Korean town of Kosŏng on the east coast. It was long believed that the Korean people originally may have had links with the people of Central Asia, the Lake Baikal region of Siberia, Mongolia, and the coastal areas of the Yellow Sea. Tools of Paleolithic type and other artifacts found in Sokchang, near Gongju, are quite similar to those of the Lake Baikal and Mongolian areas. In 2017, genetic analysis of bones found in Primorye kray in Far Eastern Russia suggested that Koreans were related to a population that had inhabited that area for at least 7,700 years. The genes of these Neolithic humans were expressed alongside those of Indigenous agriculturalists from Southeast Asia to produce the genetic structure of modern Koreans. All Koreans speak the Korean language, which is often classified as one of the Altaic languages, has affinities to Japanese, and contains many Chinese loanwords. The Korean script, known in South Korea as Hangul (Hangeul) and in North Korea as Chosŏn muntcha, is composed of phonetic symbols for the 10 vowels and 14 consonants. Korean often is written as a combination of Chinese ideograms and Hangul in South Korea, although the trend is toward using less Chinese. A large number of English words and phrases have crept into the language—either intact or modified by local usage—as a result of the American presence in the country since 1950.