Korean script has been purposefully invented for a single language (Korean). It is among the easiest scripts to learn.
Some 63 million people (1% world total) uses it.
Korean (hangul) letters
Korean characters may seem as difficult and manifold as Chinese but in fact they are few in number and among the easiest ones to learn. This is because what one could perceive to be a Korean character is in fact a combination of characters that represents a single syllable.
Such syllables consist of up to 3 characters, each character represenintg a sound. “Initial” character (top) represents the first consonant, “medial” (middle) character means vowel and “final” character (bottom if at all) represents the consonant after the vowel.
History of Korean script (hangul)
Most popular scripts have evolved naturally but Hangul is “artificial”; it has been established by a decree of king Sejong in 1443-1444. Carefully researched it was made easy to learn. Loved by the poor Hangul was initially dismissed by the elite who continued to use Chinese script (known locally as hanja).
When Korea was a Japanese colony (19th century) a combines writing system was created Japanese-style; some words would be written in hanja and most words in hangul.
In 1945 Korea was partitioned into communist North and capitalist South. North completely abandoned hanja in favor of hangul. South continued to use both but the number of hanja words decreased and unofficial literature also tend to be hangul-alone.