difference between rem and em css
Explanation: If you run these code you understand differences between rem vs em In this example, font-size of first h1 is 48px (nearest parent) and font-size of second h1 is 32px ( parent of page which is html) <style> html { font-size: 32px; } .font { font-size: 48px; } .em { font-size: 1em; } .rem { font-size: 1rem; } </style> <body> <div class="font"> <h1 class="em">Hey guys!</h1> </div> <div class="font"> <h1 class="rem">Hey guys!</h1> </div> </body>