The class global attribute is a space-separated list of the case-sensitive classes of the element. Classes allow CSS and JavaScript to select and access specific elements via the class selectors or functions like the DOM method document.getElementsByClassName.

Though the specification doesn't put requirements on the name of classes, web developers are encouraged to use names that describe the semantic purpose of the element, rather than the presentation of the element. For example, attribute to describe an attribute rather than italics, although an element of this class may be presented by italics. Semantic names remain logical even if the presentation of the page changes.

• All global attributes.
• element.className
• element.classList
• Introduction to CSS