The advancement from one position to another with an increase in duties and responsibilities as authorized by law, and usually accompanied by an increase in salary. Apparently, the indispensable element for there to be a promotion is that there must be an "advancement from one position to another" or an upward vertical movement of the employee's rank or position. Any increase in salary should only be considered incidental but never determinative of whether or not a promotion is bestowed upon an employee. (Source)