Korean is a language isolate, meaning that there is no genealogical relationship with other languages.
In the 1440s the Korean Hanja writing system, which was based on the Chinese script, was replaced with a phonetic alphabet called “Hangul” by King Sejong the Great. Korean also used to be written from top-to-bottom and right-to-left but these days it is written left-to-right in rows.
Korean includes many “counting words” where you would use a different word depending on what you are counting. For people, you would add “bun”, “geuru” for trees, “tol” for uncooked rice and “tong” for watermelons, for example.