Use of the class attribute in an HTML document:
The class attribute is supported in all major browsers.
The class attribute specifies one or more classnames for an element.
In HTML5, the class attribute can be used on any HTML element (it will validate on any HTML element. However, it is not necessarily useful).
In HTML 4.01, the class attribute cannot be used with: <base>, <head>, <html>, <meta>, <param>, <script>, <style>, and <title>.
|classname||Specifies one or more class names for an element. To specify multiple classes, separate
the class names with a space, e.g. <span class="left important">. This allows you to
combine several CSS classes for one HTML element.
Add multiple classes to one element
How to add multiple classes to one HTML element.
Your message has been sent to W3Schools.