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.
With Php, you can add unlimited additional features to your Website or Web Page, such as Forms, Sliders, Galleries, Posts and even Chatrooms.
CSS is designed to enable the separation of presentation and content, including layout, colors, and fonts. This separation can improve content accessibility; provide more flexibility and control in the specification of presentation characteristics; enable multiple web pages to share formatting by specifying the relevant CSS in a separate .css file, which reduces complexity and repetition in the structural content; and enable the .css file to be cached to improve the page load speed between the pages that share the file and its formatting.
In addition to HTML, other markup languages support the use of CSS including XHTML, plain XML, SVG, and XUL.