well PHP + mysql makes dynamic news/blog/etc sites really easy since they extract the data from a database and then use a template and host them up, for normal html you have to reupload for every update you make on the news or blog site. But with PHP, you could have a form with all the standard fields such as:
Name:
Date:
Title:
Message:
And so on, and on the actually thing it will display how ever you manipulate the info.
Therefore if you want to make a dynamic data driven website, PHP is the way to go.