A structural remedy is one in which the court orders that the divisions of a
company which has been found guilty of antitrust violations be reorganized so as
to render their monopoly inconsequential and take away their advantages in the
market. Structural remedies often include division of the company into competing
firms or the placement of firewalls between divisions, which preclude
cooperation between them.
A behavioral remedy is one which places restrictions and prohibitions on the behavior of corporations which have been found in violation of antitrust laws. The firm is essentially placed under stricter rules and is not allowed to engage in antitrust violations or compete with full force, somewhat akin to tying one hand behind their back. They often come in the form of injunctions, or court orders, and consent decrees.