Magento Cron diagrams
These diagrams show how Magento Cron works and the differences between the old and new implementation.
The diagram for Magento < 2.3.5
This is old implementation.
The diagram for Magento >= 2.3.5
This is new implementation that uses Magento Lock Framework.
Follow this link to see more information: Cron and locks + warm-up with Bohdan Korablov and Oleksandr Shmyheliuk