Sino-Korean words are one of the three main types of vocabulary in Korean. The other two are native Korean words and foreign words imported from other languages, mostly from .
Although Sino-Korean words today make up about 60% of the Korean vocabulary, many Sino-Korean words have been replaced in North Korea with native Korean words. However, there are still a large number of such words in widespread usage in the North.
Much like Japanese, a great deal of Sino-Korean vocabulary was directly borrowed from Chinese. However, a small number of Sino-Korean words were coined by the Koreans themselves. Furthermore, many academic and scientific terms were borrowed from , which had created a large body of by coining or reusing Chinese words to translate Western terminology . Under the Japanese annexation, this vocabulary was borrowed into Korean by systematically reading the characters with Korean pronunciations.
Although most ''hanja-eo'' have the same meanings as their Chinese cognates, there are cases where the Korean meaning is different from the Chinese. This is due to various causes, including divergence of Korean meanings from Chinese, Korean coinage of new words, or borrowing from Japanese. The table below contains some words that are different between Chinese and Korean, although speakers of either language might be able to guess at the meanings from the written form :
! English !! Korean !! Korean !! Chinese
| letter || 便紙, 片紙 || ?? || 信/信函/書箋/信�br />
Some Sino-Korean words derive from Japanese ''kun'yomi'' words, that is, native Japanese words written in Chinese characters. When borrowed into Korean, the characters are given Sino-Korean pronunciations.