When I think of exposures I think of houses nearby or maybe a propane tank. Sometimes this means the apartment next door or above. Never has it occurred to me that the exposure could be the countryside.
As you can see in this video, their exposure is the potential of this house fire turning into a brush fire or wildfire that could consume acres of land and other houses.
Check out this unique view of a house fire with planes and helicopters, maybe even hotshot crews operating at in California. Their definition of exposures is certainly deeper than mine!
Generally, the best method of exposure protection is to knock down the main body of fire as quickly as possible.