What is the difference between Django and Joomla?
Or better still what is the difference between CMSs (Joomla, Drupal, etc) and Web Frameworks (Django, Symphony, Zend, etc)?
Using toy construction kit analogy-
CMS: Comparable to a doll house kit. You can customize it quite a bit, but it's well suited for building mainly one kind of toy.
Web Application Framework: Comparable to a Lego set. you can build various kind of toy structures rapidly as you don't need to make the left bricks yourself.
no Framework: Developing web apps only with a programming language's standard library is like making toys out of plain clay. It offers most freedom, but you also pay the price of making all the pieces yourself.