Thanks to technology advancements, there are many different content management systems to choose from. While they have different functionalities, they also share key features. But before we jump into the key features, you should know that a content management system is made up of two main parts: the frontend and backend.
Separation of formatting and content also makes it feasible to present the same markup page in different styles for different rendering methods, such as on screen, in print, by voice (via speech based browser or screen reader), and on Braille based tactile devices. CSS also has rules for alternate formatting if the content is accessed on a mobile device.
Instead of building your own system for creating web pages, storing images, and other functions, the content management system handles all that basic infrastructure stuff for you so that you can focus on more forward facing parts of your website.
In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.