Table salt or just plain ‘salt’ as most people refer to it is actually a compound called Sodium Chloride. Its chemical symbol is NaCl.
Substitute salt is usually made up of Potassium Chloride. Its chemical symbol is KCl.
Both are salts. However, in every day language we usually mean NaCl when we say ‘salt’. It is the kind of salt we use on our food.
So why would we use ‘substitute salt’. One possible reason is that a doctor tells you to switch.
He might do that because of concerns that NaCl may contribute to hypertension (high blood pressure)
There is some debate about whether NaCl actually contributes to hypertension or not. Many doctors believe it does, but there are some out there who think that is just not true.
KCl and NaCl taste very similar.
Before you change to substitute salt in your diet (KCl), check with your doctor. There are reasons why a person would not want to use KCl, especially in the case of kidney disease.
If you have a follow up question, feel free to ask.