Mandarin or Guanhua (北方話 or 官話) is a family of related languages spoken across most of northern and southwestern Mainland China. The Mandarin dialect spoken in Beijing (Peking) functions as the official spoken language of the People's Republic of China (Standard Chinese or Putonghua), the official language of the Republic of China (Taiwan) (Guoyu), and one of the official languages of Singapore.
Source: http://www.hellomandarin.com