When do we use parentheses in negative numbers?

I heard that we only use parentheses in negative numbers to avoid confusion between subtraction and negative numbers. However, I was doing Khan Academy today and I saw this "Remember that a negative sign is only part of the base of an exponent if it is inside the parentheses with the base". So, if using parentheses with negative numbers could potentially affect an entire equation, when do we use parentheses with negative numbers?