source: http://en.wikipedia.org/wiki/Standard_Chinese ; http://zh.wikipedia.org/wiki/%E7%8F%BE%E4%BB%A3%E6%A8%99%E6%BA%96%E6%BC%A2%E8%AA%9E
The Ming Dynasty (1368–1644) and the Qing Dynasty (1644–1912) began to use the term guānhuà (官话/官話), or "official speech", to refer to the speech used at the courts. The term "Mandarin" is borrowed directly from Portuguese. The word mandarim was first used to name the Chinese bureaucratic officials (i.e., the mandarins), because the Portuguese, under the misapprehension that the Sanskrit word (mantri or mentri) that was used throughout Asia to denote "an official" had some connection with the Portuguese word mandar (to order somebody to do something), and having observed that these officials all "issued orders", chose to call them mandarins. The use of the word mandarin by the Portuguese for the Chinese officials.
From this, the Portuguese immediately started calling the special language that these officials spoke amongst themselves (i.e., "Guanhua") "the language of the mandarins", "the mandarin language" or, simply, "Mandarin". The fact that Guanhua was, to a certain extent, an artificial language, based upon a set of conventions (that is, the various Mandarin dialects for grammar and meaning, and the specific dialect of the Imperial Court's locale for its pronunciation), is precisely what makes it such an appropriate term for Modern Standard Chinese (also the various Mandarin dialects for grammar and meaning, and their dialect of Beijing for its pronunciation).
Standard Chinese or Modern Standard Chinese, also known as Mandarin or Putonghua.
