An administrator is a person who ensures that an organization operates efficiently. Administrators often manage operations and make decisions that promote the overarching goals of their areas. Their specific duties depend on the type of company, organization, or industry they work in. For example, an administrator in the construction industry may be responsible for organizing project meetings, typing up documents, responding to business inquiries, drawing up contracts, and providing customer service. An administrator could also be somebody the court appoints to manage the affairs of a company, specifically to manage the affairs of a business that has become insolvent. In this context, an administrator is responsible for settling all financial matters related to a decedents estate.

The term "administrator" is used in various other contexts, such as state administrators, pension plan administrators, and third-party administrators. In the context of computer networks, an administrator is a person who manages a computer network or system.

In general, administrators are in charge of administration, which refers to activities that deal with organizing and managing the work of a business. Their roles are integral to the organization in which they work, and their functions typically comprise a wide set of duties, including filing and management.