Django has a built in capability to create and make use of user accounts. The built-in authentication and authorization system is quite robust. More advanced applications can replace the user model with their own model as long as thy meet the requirements of the rest of Django with respect to the authentication and authorization system.

Forms are the way that web applications present users with pages that areas to be filled in and sent to the server as data. Django has extensive support to simplify how we write code to interact with HTML forms.

As we design our data models, it is important to follow normal-form and not replicate string data. We do this by using multiple tables and making link between rows of two tables. The one-to-many pattern is one technique to replace data replication using links between rows in different tables.

This module covers the important technique of marking rows in a data model as belonging to a particular user. With this information we can decide who can edit or view particular rows. We look at how we can use Django with object-oriented Python to build a reusable "owned rows" feature.

The more advanced data modeling approach to remove replication of string data is the Many-To-Many data model. Sometimes a one-to-many model is not flexible enough to represent structures like course rosters. A Many-to-many model in essence models two on-to-many relationships.