What does the 'important' rule do in CSS?

The 'important' rule in CSS serves to increase the priority of a specific CSS declaration. When a style rule is marked with !important, it overrides any other conflicting styles, regardless of their specificity. This means that if there are multiple styles applied to an element, and some of them have different levels of specificity, the rule marked as !important will take precedence.

For example, if there are two conflicting styles where one has higher specificity but lack the !important tag, the rule with !important will be applied, ensuring that it wins over others. This is particularly useful in situations where inline styles or styles from external stylesheets need to be overridden.

The other options do not accurately describe the function of !important. While it's true that it prevents other rules from overriding its declarations, it does not correlate directly to simply increasing specificity or being limited to print styles. Instead, it fundamentally alters the priority assigned to a style, ensuring that it is applied above other styles unless another !important rule of an even higher specificity is encountered.