Selector (CSS)

In CSS, a selector is a pattern matching rule that determine which style rules apply to elements in the document tree.

Description

If all conditions in the pattern are true for a certain element, the selector matches the element.

Selectors may range from simple element names to rich contextual patterns.

The case-sensitivity of document language element names in selectors depends on the document language.

For example, in HTML, element names are case-insensitive, but in XML they are case-sensitive.