As it is the case with all other national languages in the world, Standard Chinese is not a uniform, homogenous entity. In few countries through a long history of universal compulsory education, rigorous extermination of dialects and intensive populace transmigration, a certain uniformity in language has been achieved (most notably in France and Russia). Meanwhile, Chinese has 2 official scripts, 5 types of romanization, 15 major mutually unintelligible dialects and uncountable local varieties.
Mandarin
Mandarin, that is supposed to be THE communication medium for all the Chinese, is the mother tongue of only a part of the population in Mainland China and Taiwan, being the language of education for the rest, while Mandarin proficiency rate among the Overseas Chinese (huaren) is highly debatable and once again is subject to formal education.
Script
2 official scripts of Chinese are Traditional and Simplified. While the former, true to its name, uses mostly archaic forms, the latter, introduced in the 50s in PRC (People's Republic of China) for the sake of universal education promotion, has the number of strokes in a majority of symbols reduced. Traditional characters are used in Taiwan, Hong Kong (Xianggang), Macau (Aomen) and Overseas community. Simplified ones are in official use in Mainland China. With growing China's affluence in recent years, Singapore has aptly switched to the Simplified script, too.
Romanization
5 main types of romanization include: Wade-Giles, Pinyin, Zhuyin, BoPoMoFo and the French system. Once again there is a regional difference in usage: Pinyin is the standard in Mainland China (and increasingly in the world), and Wade-Giles in Taiwan. Thus, my Taiwanese friend's name Chou Ji-hsin in China would be transcribed as Zhou Ri-xin.
Most of dialects/languages are spoken in Southern China, while in the North, ethnic Chinese almost invariably speak the Han dialect whereon Mandarin is based.Cantonese has gained by far the highest profile among other dialects thanks to Hong Kong blockbusters and Canto-pop. It is spoken by estimated 60 million people in China, Hong Kong, Macau and by many Overseas Chinese. It has 6 (some say 9) tones.
Other more or less known dialects are:
All this astounding diversity should not discourage the beginner. Standard Mandarin that you are most likely to study is the language of literature, education, media and communication in what is already the 3rd largest economy in the world populated by some 1,300,000,000 people. It is also the language of the 4-thousand-year written tradition that has got vast treasures of literature for you to discover.
