Dag Definition

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.. dag-definition-start A Dag is a model that encapsulates everything needed to execute a workflow. Some Dag attributes include the following:

• Schedule: When the workflow should run.
• Tasks: :doc:tasks </core-concepts/tasks> are discrete units of work that are run on workers.
• Task Dependencies: The order and conditions under which :doc:tasks </core-concepts/tasks> execute.
• Callbacks: Actions to take when the entire workflow completes.
• Additional Parameters: And many other operational details. .. dag-definition-end

.. dag-etymology-start .. note::

The term "DAG" comes from the mathematical concept "directed acyclic graph", but the meaning in Airflow has evolved well beyond just the literal data structure associated with the mathematical DAG concept. Therefore it was decided to use the term Dag in Airflow.

.. dag-etymology-end