freeCodeCamp Basic CSS. Understand Absolute versus Relative Units
https://www.freecodecamp.org/learn/responsive-web-design/basic-css/understand-absolute-versus-relative-units Understand Absolute versus Relative Units The last several challenges all set an element's margin or padding with pixels (px). Pixels are a type of length unit, which is what tells the browser how to size or space an item. In addition to px, CSS has a number of different length unit optio..