What is the authentication mechanism on prefect server. When i started prefect server it automatically launched Client as well and did not asked any authentication.

Prefect Server does not handle any form of authentication for you, and last I checked any 3rd party code that adds any form of security to Prefect Server is not supported or endorsed by Prefect. If you want to add security to your Prefect Server instance, you can either write your own solution to integrate with Server or use Prefect Cloud, which has security included out of the box!

Secret objects in Prefect are used to provide sensitive information to the workflow like authentication parameters of any third party app. Is my understanding correct?

Secret objects in Prefect are used to provide sensitive information to the workflow like authentication parameters of any third party app. Is my understanding correct?

Correct! I believe but am not 100% sure that you can use Secret objects (with the

use_local_secrets

flag set to

True

) without Prefect Cloud.

I could not find any documentation on user management with prefect server or prefect core. Is user management possible on prefect server. Is which user triggered which task tracked?

User management is possible with Prefect Cloud, but explicitly not handled in Prefect Server. Using Prefect Cloud, you create tokens with differing permissions for different parts of the workflow. For example, the Agents should have a Runner scoped token associated with them. When the tokens are generated, certain information about your Prefect Cloud account is embedded into them, depending on the scope of the token and some other factors. For reference, here is the link to the docs for Secrets https://docs.prefect.io/orchestration/concepts/secrets.html#setting-a-secret.