I agree with encylo..Static sites are meant for those sites that cant be changed or updates regularly.
and Dynamic sites are those sites that changes or update regularly.
Dynamic websites can make the most of your site and either use it as a tool or create a professional, interesting experience for your visitors.
Joomla is a great CMS, Iíve tried a bunch of them and chose that one because it has a ton of people developing extensions for it, they are mostly free and run pretty good. The best CMS is one that is custom built. You can specify the requirements, security and design is not restrictive. Wordpress is also favorite cms, although itís a blog engine!