CMS helps to separate design of web site from its content. It means designer develops a web site and gives it to its owner or manager who can fill a certain design with different content. If necessary the content of web site, its images and graphics can be easily edited without intervention into design of web site. All changes become visible as soon as you make them. (Don‘t forget to reload page after making changes). Even if you are not an expert of HTML coding, you can easily manage the content of your web site yourself.
If we directly insert the content, we will create a new page template for each page of the site. But this is fine since we are not duplicating the header, footer and sidebar. To reduce the number of page templates, we can store our content in a database and use a page ID to identify which page content to insert. This ID is usually appended to our URLs of the website. If we do this, we are creating what is known as a Content Management System (CMS). Where the theme is likely to be changed often or people are encouraged to design new themes, a separate directory can be created to hold the various themes. A read me file could be included to credit the designer, or this information could be added to the start of the style sheet as a comment section.