The New York City Police Department (NYPD) is structured into numerous bureaus and units. As a whole, the NYPD is headed by the Police Commissioner, a civilian administrator appointed by the Mayor, with the senior sworn uniformed officer of the service titled "Chief of Department". The Police Commissioner appoints the First Deputy Commissioner as the department's second-in-command and the Chief of Department as the department's highest ranking uniformed officer. The commissioner also appoints a number of deputy and assistant commissioners who do not have operational command and are solely for support and administrative function. The department is divided into twenty bureaus, six of which are enforcement bureaus. Each enforcement bureau is further subdivided into sections, divisions, and un