In a traditional in-ground pool decontaminating process, chlorine mixes with organic matter - sweat, saliva, dandruff, urine, and turns into other chemicals, including chloramines. The source of the chlorine smell in a pool is the chloramines which have become airborne.
Since the salt water generators deliver a constant stream of chlorine, they make the chloramines less of an issue. This impact is most noticeable in that it is less irritating to the eyes and skin of swimmers. The salinity is about 1/12 of that of the ocean.
One big advantage of the salt water pool is that by generating chlorine, the pool owner doesn't have to purchase chlorine, nor go through storing and administering chemicals to the pool. Although this may mean more safety for one's health.