A CMS enables website owners to edit some or all of their website by using an online interface. Owners can log onto a secure section of their website and use a Microsoft Word-like interface to edit parts of their own website, rather than getting their web developer to make changes for them.
CMS' are more expensive to setup because all information is stored in database tables rather than individual files, but if regular editing of the site is required, a CMS can be cheaper in the longer term.
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