pH is the chemistry terminology for "Power of the Hydrogen Ion" in solution. Having a lot of hydrogen ions floating around (a low pH) in solution makes it acidic, and it will be corrosive, attacking some metals and other things. Not so many hydrogen ions floating around results in a solution with a high pH which is basic. pH is an inverse logarithmic scale which runs from 1 to 14. Pure water has a neutral pH value of 7. Any value higher is basic, anything lower is acidic. For example, a solution of hydrochloric acid will have a pH of less than 1. A solution of sodium hydroxide (lye) will have a pH of 14, as very few free hydrogen ions are available. . It's important to recognize that pH makes sense only when referring to aqueous solutions of soluble substances. The concept makes no sense regarding wax. If you want to look up pH on Wikipedia, you can find a lot more than you probably wish to know.