The Korean alphabet, known as Hangul in South Korea and Chosŏn'gŭl in North Korea, is a writing system for the Korean language first created by King Sejong the Great in 1443. The letters for the five basic consonants reflect the shape of the speech organs used to pronounce them, and they are systematically modified to indicate phonetic features; similarly, the vowel letters are systematically modified for related sounds, making Hangul a featural writing system. It has been described as a syllabic alphabet as it combines the features of alphabetic and syllabic writing systems.Hangul was created in an attempt to increase literacy by serving as a complement or an alternative to the logographic Sino-Korean Hanja, which has been used by Koreans as its primary script to write the Korean language since as early as the Gojoseon period, along with the usage of Classical Chinese. As a result, Hangul was initially denounced and disparaged by the Korean educated class as eonmun (vernacular writing; 언문, 諺文), and it only became the primary Korean script in the decades following Korea's independence from Japan in the mid-20th century.Modern Hangul orthography uses 24 basic letters: 14 consonant letters and 10 vowel letters. There are also 27 complex letters formed by combining the basic letters: 5 tense consonant letters, 11 complex consonant letters and 11 complex vowel letters. Four basic letters in the original alphabet are no longer used: 1 vowel letter and 3 consonant letters. The Korean letters are written in syllabic blocks with the alphabetic letters arranged in two dimensions. For example, Hangeul in Korean is written as 한글, not ㅎㅏㄴㄱㅡㄹ. These syllables begin with a consonant letter, then a vowel letter, and then potentially another consonant letter (Korean: 받침; RR: batchim). If the syllable begins with a vowel sound, then the consonant ㅇ (ng) will act as a silent placeholder. However, when ㅇ starts a sentence or is placed after a long pause, it makes the glottal stop sound.

Syllables may begin with basic or tense consonants, but not complex ones. The vowel can be basic or complex, while the second consonant can be basic, complex or a limited number of tense consonants. The way the syllable is structured depends if baseline of the vowel symbol is horizontal or vertical; if the baseline is vertical, the first consonant and vowel are written above the second consonant (if present,) whereas all of the components are written individually top to bottom in the case of a horizontal baseline.As in traditional Chinese and Japanese writing as well as many other texts in East Asia, Korean texts were traditionally written top to bottom, right to left, and are occasionally still written this way for stylistic purposes. Today, it is typically written from left to right with spaces between words. It is the official writing system of Korea, including both North and South Korea. It is a co-official writing system in the Yanbian Korean Autonomous Prefecture and Changbai Korean Autonomous County in Jilin Province, China.