• Project: The entire Django application containing settings, configurations, and multiple apps
• App: A sub-module within a project that handles specific functionality

A project can contain multiple apps, and apps can be reused across different projects. Apps should follow the single responsibility principle - each app should have one clear purpose.

Example structure:

myproject/          # Project
├── blog/          # App
├── users/         # App
├── settings.py    # Project settings
└── urls.py        # Project URLs