Office administration is a set of day-to-day activities related to financial planning, billing and recordkeeping, personnel, and physical distribution and logistics, within an organization. An employee that undertakes these activities is commonly called an office administrator or office manager. The exact duties of an office administrator vary depending on the employer and level of education.[1]

Office administration includes planning work assignments for and supervising staff, requesting new office equipment and repairs on existing equipment.[2][3][4] Office administrators also handle duties such as customer service, payroll, and implementing department policies and changes. They also discuss performance problems with employees and work with upper management to hire new employees or dismiss current employees.[5]
https://en.wikipedia.org/wiki/Office_administration