Party that has express (oral or written) or implied authority to act for another (the principal) so as to bring the principal into contractual relationships with other parties. An agent is under the control (is obligated to) the principal, and (when acting within the scope of authority delegated by the principal) binds the principal with his or her acts. Additional powers are assigned to agent under the legal concept of 'apparent authority.' The agent, however, does not have title to the principal's goods in his or her possession, except where agent's lien is applicable. In general, advertising agencies do not fall under this definition of an agent, because they act as principals for the services they buy on behalf of their clients. See also general agent, special agent, and universal agent.