Agency is either actual or apparent. An agent has such authority as the principal actually or apparently confers on the agent. A principal is bound by the acts [or omissions] of the agent.
Actual authority exists when the principal confers authority on the agent, or intentionally or through lack of ordinary care, leads the agent to believe that the agent has been given such authority.
Apparent authority exists when the principal intentionally, or by lack of ordinary care, causes or allows a third person to believe that another is acting as the principal's agent.