Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It is known for its "batteries-included" approach, providing built-in tools and libraries for various aspects of web development, such as authentication, database interaction, and URL routing.

In Django, an app is a self-contained module that performs a specific function. Apps are reusable, making it easy to separate different functionalities within a project. A Django project can have multiple apps, each responsible for a different part of the application.

Django models are Python classes that define the structure of your database tables. Each model corresponds to a table, and each attribute of the model represents a database field. Models are defined in an apps models.py file.