My understanding is: a pure substance composed of metal ions and chloride ions or metal ions and acid ions. The pure substance composed of ammonium ion and chloride ion or ammonium ion and acid ion is also salt, which is called ammonium salt [it can also be classified by acid ion, such as ammonium nitrate is ammonium salt and nitrate, and ammonium sulfate is ammonium salt and sulfate].

Acid ion is nitrate NO3-, carbonate CO3- and sulfate SO? 2+ and so on, ammonium ion is NH? +

Such as sodium chloride NaCl, calcium carbonate CaCO3, ammonium chloride NH? Cl and ammonium nitrate NH4NO3 are all salts. Then if the solution obtained by dissolving salt in water is called salt solution, the PH value of salt solution is not necessarily neutral. The main component of our usual edible salt is sodium chloride.