Hanja (Hangul: ; Hanja: , ha(ː)ntɕ͈a), alternatively known as Hancha, are Chinese characters () used in the writing of Korean. Hanja was used as early as the Gojoseon period under the first Korean kingdom.
Hanja-eo (한자어, ) refers to Sino-Korean vocabulary, which can be written with Hanja, and hanmun (한문, ) refers to Classical Chinese writing, although Hanja is also sometimes used to encompass both concepts. Because Hanja characters have never undergone any major reforms, they more closely resemble Japanese Gujache (구자체, ) and traditional Chinese characters, although the stroke orders for certain characters are slightly different. Such examples are the characters and , as well as and . Only a small number of Hanja characters were modified or are unique to Korean, with the rest being identical to the traditional Chinese characters. By contrast, many of the Chinese characters currently in use in mainland China, Malaysia and Singapore have been simplified, and contain fewer strokes than