An administrator is responsible for carrying out both administrative and strategic functions of a business. A manager is responsible for executing the daily strategic workflow of a business.
An administrator's essential job functions include handling the legal aspects of a company regarding staffing and payroll and ensuring the company is in compliance with legal obligations. Some administrators also are responsible for human resources.
A manager oversees the departmental structure of a business to ensure that each department runs smoothly. A manager works to accomplish the broad objectives of a company and is responsible for a team, a staff or a group of people.