How Airflow Works?¶

Scheduler: handles both triggering scheduled workflows, and submitting Tasks to the executor to run. The executor, is a configuration property of the scheduler, not a separate component and runs within the scheduler process. There are several executors available out of the box, and you can also write your own.
Dag Processor: parses DAG files and serializes them into the metadata database
Web Server: presents a handy user interface to inspect, trigger and debug the behaviour of dags and tasks.
Metadata Database: Airflow components use to store state of workflows and tasks.
Worker (Optional): executes the tasks given to it by the scheduler.
Triggerer (Optional): executes deferred tasks in an asyncio event loop