What is CMS website design? You should first understand what a CMS is. It stands for Content Management System and it does just that. It's an easy way to manage content on your content management website and there are tons of advantages. Basically, you can login to your Content Management System website design website using just your web browser. No other software is needed. You find the page you want to edit, edit that page using a word processor-like interface, save your changes and then your Content Management System website design website is instantly updated.