Airflow is a platform created by Airbnb to automate and schedule workflows. It uses a Directed Acyclic Graph (DAG) structure to define dependencies between tasks, and allows scheduling tasks on a timetable or triggering them manually. Some key features include monitoring task status, resuming failed tasks, backfilling historical data, and a web-based user interface. While additional databases are required for high availability, Airflow provides a flexible way to model complex data workflows as code.