A more thorough explanation:

Definition: Ex officio is a Latin term that means “by virtue of the office.” It refers to a job or task that is automatically assigned to someone because of another title they hold.

For example, the CEO of a company may also be a member of the board of directors ex officio. This means that they are a member of the board simply because they hold the position of CEO. Another example is the Vice President of the United States, who presides over the U.S. Senate on certain matters as part of their role as Vice President.

An ex officio role can be a ceremonial position or a managerial position, depending on the circumstances.

Example: The Dean of a college may be an ex officio member of the faculty senate. This means that they are automatically a member of the senate because of their position as Dean.

This example illustrates the definition of ex officio because the Dean is not elected or appointed to the faculty senate, but rather is a member by virtue of their position as Dean.