Project & App Structure

Django draws a line between a project (the whole site, its settings, its top-level URL routing) and an app (one self-contained feature — a blog, a store, a polls feature). A project can contain several apps; a well-designed app can even be reused across different projects.

What startproject generates

Running django-admin startproject mysite creates this layout:

mysite/
    manage.py
    mysite/
        __init__.py
        settings.py
        urls.py
        asgi.py
        wsgi.py

manage.py is the command-line entry point for everything — running the dev server, creating migrations, opening a Python shell wired up to your project. Inside the inner mysite/ folder, settings.py holds every configuration option (database connection, installed apps, timezone), and urls.py is where URL patterns for the whole project get routed.

Adding an app

A project on its own doesn't do anything yet — you add apps to it. From the same directory as manage.py:

python manage.py startapp blog

blog/
    migrations/
        __init__.py
    __init__.py
    admin.py
    apps.py
    models.py
    tests.py
    views.py

Each of these files has one job: models.py is where you'll define the app's data (lesson 5), views.py is where request-handling logic goes (next lesson), admin.py registers models with Django's built-in admin (lesson 6), and migrations/ stores the generated history of changes to your models.

Registering the app

Creating an app's folder doesn't automatically activate it — Django needs to be told it exists, in settings.py:

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'blog',
]

The six django.contrib.* entries already there are Django's own built-in apps — the admin site, the authentication system, session handling — installed the exact same way your own apps are. Adding 'blog' to this list is what makes its models, admin registrations, and templates visible to the rest of the project.