How does Django's Meta class work?

You are asking a question about two different things:

1. Meta inner class in Django models:

   This is just a class container with some options (metadata) attached to the model. It defines such things as available permissions, associated database table name, whether the model is abstract or not, singular and plural versions of the name etc.

   Short explanation is here: Django docs: Models: Meta options

   List of available meta options is here: Django docs: Model Meta options

   For latest version of Django: Django docs: Model Meta options

2. Metaclass in Python:

   The best description is here: What are metaclasses in Python?

Extending on Tadeck's Django answer above, the use of 'class Meta:' in Django is just normal Python too.

The internal class is a convenient namespace for shared data among the class instances (hence the name Meta for 'metadata' but you can call it anything you like). While in Django it's generally read-only configuration stuff, there is nothing to stop you changing it:

In [1]: class Foo(object):
   ...:     class Meta:
   ...:         metaVal = 1
   ...:         
In [2]: f1 = Foo()
In [3]: f2 = Foo()
In [4]: f1.Meta.metaVal
Out[4]: 1
In [5]: f2.Meta.metaVal = 2
In [6]: f1.Meta.metaVal
Out[6]: 2
In [7]: Foo.Meta.metaVal
Out[7]: 2

You can explore it in Django directly too e.g:

In [1]: from django.contrib.auth.models import User
In [2]: User.Meta
Out[2]: django.contrib.auth.models.Meta
In [3]: User.Meta.__dict__
Out[3]: 
{'__doc__': None,
 '__module__': 'django.contrib.auth.models',
 'abstract': False,
 'verbose_name': <django.utils.functional.__proxy__ at 0x26a6610>,
 'verbose_name_plural': <django.utils.functional.__proxy__ at 0x26a6650>}

However, in Django you are more likely to want to explore the _meta attribute which is an Options object created by the model metaclass when a model is created. That is where you'll find all of the Django class 'meta' information. In Django, Meta is just used to pass information into the process of creating the _meta Options object.

Django's Model class specifically handles having an attribute named Meta which is a class. It's not a general Python thing.

Python metaclasses are completely different.