While making a site using web templates a person can make a base template file where it is possible to specify the non editable and editable regions separately. People also prefer the template based sites as they tend to be search engine friendly if the template is optimized properly. One can take the help of certain web site design software like Dream weaver for creating website templates easily. However, it also helps if one knows HTML to an extent.
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.