A good place for most of us would be to read this primer on Whats So Special about Special Districts? This fourth edition of the Citizen’s Guide to Special Districts (pdf) was put together by the Senate Local Government Committee in October 2010 and explains what special districts are, their history, authority, legal powers, and different ways to understand them. As it says in the first paragraph of the guide, “Most of us don’t know much about local governments. We know less about special districts. Special district advocates hail special districts as the best examples of small-town democracy. Their critics say that special districts make local government too complex. What’ s So Special About Special Districts? untangles the basic facts about this least known segment of local government.”
Too busy to read the whole primer? How about this 2 pager: SPECIAL DISTRICT FACT SHEET — Senate Local Government Committee, August 2009 (pdf)
Bottom line – Fire Districts are Special Districts, with a single function to provide fire protection in their geographic area. There are multiple fire districts in Santa Cruz County. Here is a map of all the fire service areas/ districts in Santa Cruz County (pdf).