Pinyin

In pinyin, each Chinese syllable is spelled in terms of an optional initial and a final, each of which is represented by one or more letters. Initials are initial consonants, whereas finals are all possible combinations of medials (semivowels coming before the vowel), a nucleus vowel, and coda (final vowel or consonant). Diacritics are used to indicate the four tones found in Standard Chinese, though these are often omitted in various contexts, such as when spelling Chinese names in non-Chinese texts.
Hanyu Pinyin was developed in the 1950s by a group of Chinese linguists including Wang Li, Lu Zhiwei, Li Jinxi, Luo Changpei and Zhou Youguang, who has been called the "father of pinyin". They based their work in part on earlier romanization systems. The system was originally promulgated at the Fifth Session of the 1st National People's Congress in 1958, and has seen several rounds of revisions since. The International Organization for Standardization propagated Hanyu Pinyin as ISO 7098 in 1982, and the United Nations began using it in 1986. Taiwan adopted Hanyu Pinyin as its official romanization system in 2009, replacing Tongyong Pinyin. Provided by Wikipedia