The basic letters of the alphabet when Hunmin-jeongeum was first created numbered eight; they were the vowels "¤·, ¤Ñ, ¤Ó" and the consonants "¤¡, ¤¤, ¤±, ¤µ, ¤·"
The vowels were created in the image of the sky, land, and man. That is '¤·' resembles the roundness of the heaven, '¤Ñ' represents the flat earth and '¤Ó' is the image of a standing man.
The other vowels are variations of these three basic vowels.
When first proclaimed by King Sejong, Hunmin-jeongeum had 28 letters in all, of which only 24 are in use today. The 24 letters are consonants 14 and vowels 10.
The reason consonants and vowels were separated was due to their differing functions when two letters were combined to form a syllable.