Class selectors find elements with the specific class set by the HTML class attribute. A class selector is preceded by a full stop (.). For example, the selector for all elements of the class center would look like this: .center.

The class selector is the most commonly used selector type because of its flexibility — you can add the same class to different elements or multiple classes to one element.

Combining element type selectors with class selectors allows you to target elements of a specific type with a certain class. For example, to select all <h1> headings with the class center, use the selector h1.center.