CSS icons are created and styled using Cascading Style Sheets They are often used in web design to add decorative or functional icons to a website without the need for image files. CSS icons have several advantages, including scalability, easy customization, and reduced page load times. Icon libraries in CSS: Bootstrap icons Font Awesome icons Google icons Font Awesome icons Font Awesome is one of the most well-known and widely used icon libraries. It provides a collection of scalable vector icons that can be easily customized and styled using CSS classes. Icons are available in both free and paid versions.