Django is the "The web framework for perfectionists with deadlines."
What is a web framework? In analogy to LEGO. Imagine C code is the plastic of which LEGO is made of. Its hard to built something useful with raw plastic. Python code are the individual blocks/bricks. Many blocks together can be combined to construct, for instance, a multifunctional unit such as a building which is analogous to a web framework as it does all the repetitive boiler code (which each house has like roof, doors, windows) and can easily be extended by adding additional functionality to it (e.g. helicopter landing platform). Django has a very vital community and is one of the few projects where one can happily run production sites on trunk, upgrading every Tuesday.
It has many batteries included of which are database access through object relational model and form processing are just two parts from a whole bunch.