Operator precedence refers to the rules that determine the order in which different operations are performed in mathematical expressions or programming languages. For example, in the expression 3 + 5 * 2, the multiplication is performed first due to higher precedence, resulting in 3 + 10, which equals 13. Understanding operator precedence is crucial for correctly interpreting expressions. Common operators include addition, subtraction, multiplication, and division, with multiplication and division generally having higher precedence than addition and subtraction. Parentheses can be used to override these rules, ensuring that specific operations are performed first, as seen in (3 + 5) * 2.