VFD stands for Volunteer Fire Department. Many localities don't have the tax base to support a paid fire department where firefighters are on duty 24/7. Some tax dollars go toward equipment but a lot of the costs are met by having fundraisers and from donations. The firefighters live nearby and sometimes have scanners or another type of radio to receive emergency calls. There is usually a siren to alert them too.
If you require their services you may get a bill. A friend of mine accidentally started a
grass fire in his backyard and had to call the local
VFD. They came and put it out and sent him a bill for several hundred dollars.
Volunteer firemen also assist at automobile accidents and for
traffic control when necessary. In
Western Pennsylvania the volunteer firemen have flashing blue lights on their vehicles.