Propel is a full-service object persistence and query toolkit for PHP5. What this means, in practical terms, is that Propel allows you to treat your database as a set of objects, providing a simple API for storing and querying data. Other names associated with this type of tool include Object Relational Mapping (ORM) and Data Access Objects (DAO). Propel provides a generator that creates SQL and PHP classes and also provides the runtime environment for managing object persistence and retrieval.