In order to deploy Process Builders, please use the Flow component type. With the latest version of Metadata API, FlowDefinitions are not needed.
The Flow holds the logic of your process builder .
You can activate the latest version using Flosum.
Can skip version numbers in your deployment e.g. go from version 2 to version 5.
Can deploy versions lower than the active one on target. The lower one will become the active version
We cannot delete flows using Metadata API