Although most people keep salt in some sort of bowl in the kitchen, close to the stove or cooking area, they are not too cautious about where they store the rest of the package. In general, salt is pretty inexpensive, thus people will not take a lot of care when storing it. If you buy salt in bulk, or at least a pound or two at a time, you want to make sure that after filling your everyday salt bowl, you store the rest in a dry, cool place far from heat of sunlight and ideally in a closed jar.
The reason salt needs to be in a closed jar is that it will absorb moisture and aromas from other things. If you keep it open in your spice drawer, it will absorb the aromas from other herbs and spices. Be extra careful when storing higher quality types of salt like Fleur de Sel since they have a pure and delicate flavor, which is probably why you bought it in the first place, and it can be contaminated easily.
