Plain English Meaning
When a small airport has no control tower but does have a Flight Service Station on the field, that station can give you helpful information about wind, runway in use, weather, and other traffic. It's advice, not instructions — you still make your own decisions about when and how to land or take off.
Full Definition
A service provided at selected non-towered airports by a Flight Service Station (FSS) located on the field. The FSS specialist gives arriving and departing pilots information such as wind direction and speed, favored runway, altimeter setting, known traffic, NOTAMs, and . It is an only — the FSS does not traffic or issue .