What does business administrator do?

Business administration is the same as business management. This includes all aspects of business and related areas, including accounting, finance and marketing. The administration is very important for any businesses because without it the business cannot run and make any money.
What does business administration include?
Business conduct or management and decision making
the effective organization of people and other resources;
to direct actions towards common goals and objectives;
refers to a wider management function, including related financial, personnel and management information system services.

Why a is business administrator needed?
Business administrator essentially acts as the manager of the company and its other managers. Such a person monitors managerial positions to ensure that they follow the company's policies and work most effectively on achieving the company's goals.
Business administrators can work with human resources, manufacturing, finance, accounting, and marketing managers to ensure they work properly and operate in accordance with the company's goals and objectives. In addition, they can interact with people outside the company, such as business partners and vendors.