In this subtitle the following words have the meanings indicated. “Fire, rescue, or emergency medical services entity” means: a governmental subdivision, by its appropriate designated authority; a board or fire commission of a fire department or governmental subdivision; a fire department; a fire company; a rescue squad; or an emergency medical services unit, including an entity that provides emergency medical services at any level. “Mutual aid agreement” means an agreement to establish and carry out a plan to assist in extinguishing fires and preserving life and property by providing fire fighting, rescue, or emergency medical equipment, personnel, and services. “Mutual aid agreement” includes a reciprocal agreement entered into in accordance with this section and § 7–103 of this subtitle before July 1, 1989.