We utilize an exterprise-class CMS which stores all you content (news, calendar events, user information, descriptive pages, etc...) in a database and completely separates it from the design and layout. This approach pays HUGE dividends, even if you only want to make a small change such as your corporate logo. Rather than changing this on all the pages of your site, you simply update one page (the template). Since all your content is placed from the database into your template, the single layout change is immediately propogated to your entire site. 

Other features include content expiry, access control depending on login/user permission, content categorization and many more. Arguably the most important feature is that numerous content providers can be given publishing privileges for your site. Little to no programing knowledge is required and, since layout and content are separated, the design and site-wide attributes such as font size and typeface are protected from modification. The end result is that content providers can focus their efforts on good content and not on the publishing technology (i.e. the CMS itself).