Difference between flow-deployment.yaml and deployment.yaml in the project?

[FeryET]

Hello.

I'm trying to understand the differences between what does the deployment,yaml do in a prefect project in comparison with the yaml file created by prefect deployment build.

As far as I understand, I cannot add infra blocks to the deployments declared in the project specific deployment.yaml file.

What exactly is the usecase of this file, and how can I get rid of multiple deployments and collect them in a single yaml in the project?