Think of pH like a mood ring for water. It measures how acidic or alkaline (basic) something is on a scale from 0 to 14. Pure water sits right in the middle at a pH of 7, which is neutral—like a perfectly balanced cup of tea.
Anything below 7 is acidic, like lemon juice (around pH 2) or black coffee (around pH 5). Anything above 7 is alkaline, like baking soda water (pH 9) or a milky latte. That neutral 7 is where we feel most at home.