When used in this article:
1. “Districts” shall mean fire districts created pursuant to article eleven of the town law.
2. “Fire companies” shall mean fire companies governed by the not-for-profit corporation law.
3. “Municipal corporations” shall mean a county, city, town and village.
4. “Municipalities” shall mean municipal corporations.
5. “Sprinkler system” shall mean a system of piping and appurtenances designed and installed in accordance with generally accepted standards so that heat from a fire will automatically cause water to be discharged over the fire area to extinguish it or prevent its further spread.