Here's a breakdown:

* pH stands for "potential of hydrogen."

* The scale ranges from 0 to 14.

* Lower numbers indicate a higher acidity.

* Higher numbers indicate a higher alkalinity (or basicity).

* 7 is neutral. This is the pH of pure water.

For example:

* Lemon juice has a pH of around 2, making it highly acidic.

* Baking soda has a pH of around 9, making it alkaline.