# Django 1.8.18.dev20170123152445 documentation

# Models and databases

A model is the single, definitive source of data about your data. It contains the essential fields and behaviors of the data you’re storing. Generally, each model maps to a single database table.

- Models
- Making queries
- Aggregation
- Managers
- Performing raw SQL queries
- Database transactions
- Multiple databases
- Tablespaces
- Database access optimization
- Examples of model relationship API usage