If you’re referring to the taste, it’s because the process of us tasting salty water isn’t that different from us tasting salt.
Our taste buds have little receptors that detect molecules of different shapes. There are receptors for sodium and chloride ions. When we eat salt, it dissolves in our saliva, and we taste the ions. When we drink salt water, we still just taste the ions. There aren’t receptors for dry un-dissolved salt crystals, to my knowledge.
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