Guess what water with a TDS>0 has? Salt!
Remember that nail your forgot to galvanise and it catching rust? Salt!
Remember the fancy false ceiling? Salt!
Alum, used to precipitate dissolved “hardness”? Salt!
Mineral water has minerals! Salt!
So, if you’re interested in knowing about the chemicals that make the world around you, refer to you friendly neighbourhood High School Chemistry book and have FFUUNN!