Every major news and blog publication like the BBC and CNN use content management systems (CMS). The reason they use CMS is because it makes the whole process of a making a new web page a lot easier and quicker. CMS doesn't have a completely new page for every page in a website or a website like the BBC would have thousands of pages. CMS uses a template which then it adds content to, like text and images - the text is then stored in a database and the CMS will fetch that text when needed to create a page, but these pages are kind of virtual pages which are made on the fly, just switching out content in the template.
There is a huge array of CMS out there. One of the most basic, easy to use and cheapest is Wordpress. I use it myself on this website. Other big websites like the BBC and CNN also use Wordpress. Wordpress is also the most popular CMS out there with over 5 million websites using it because it's free. All you have to pay for is the hosting and maintenance.