Usually, the title “Material” positions a UI component library right at the top of the star-count and downloads count. Google’s Material-components-web library is the web-component version of the Material-UI library.
A Pseudo class in CSS is used to define the special state of an element. It can be combined with a CSS selector to add an effect to existing elements based on their states. For Example, changing the style of an element when the user hovers over it, or when a link is visited. All of these can be done using Pseudo Classes in CSS.