The Nazi Party is how the ruling (and only) party in the Third Reich is popularly referred to in the English-speaking world. The party itself, however, never referred to itself by that name because the term "Nazi" was a derogatory one coined by anti-Nazis. The full name of the party was Nationalsozialistische Deutsche Arbeiterpartei i.e. National Socialist German Workers' Party. In German-language historical texts the party is usually referred to by its German-language initials NSDAP.
The Nazi party, or NSDAP, was founded in 1919, originally as Deutsche Arbeiterpartei (DAP). Adolf Hitler soon became its dominant figure and by 1921 was its president and leader (Führer). The internal organization of the NSDAP followed the Führerprinzip, or principle of personal authority of the designated leader at all levels, a pervasive principle of Nazism that after 1933 was also implemented in the institutions of the state and in the institutions that replaced the previous institutions of civil society. The party came to power over the whole of Germany after Hitler was appointed Chancellor on 30 January 1933. All other political parties were abolished by 14 July 1933.
The Nazi party (NSDAP) was abolished by the Allies after the defeat of Nazi Germany in 1945, and designated a criminal organization in the Nuremberg trials and remains abolished in Germany.