Chemical definition of salt?
Table salt is sodium chloride (NaCl).
Salts are formed when an acid reacts with a base. The acid consists of Hydrogen and a negative ion; bases consist of hydroxyls and a positive ion. When they react, the hydrogen and hydroxyls make water and carbon dioxide and the positive and negative ions form the salt.
E.g. if you mix hydrochloric acid (HCl) and sodium bicarbonate (NaHCO3) you will get water, carbon dioxide and table salt.