Dataflow vs Dataproc

Cloud Dataflow is a fully managed service that is totally serverless data processing service which means you just have to assign a job to it and the rest dataflow will take care. Behind the scenes When you submit a job on Cloud Dataflow, it spins up a cluster(virtual machines) and distributes the tasks in your job to the VMs, furthermore, it dynamically scales the cluster based on how the job is performing. 

Dataflow supports both batch and streaming jobs. It can be integrated with Pub/Sub for stream processing and with other services like BigQuery and Cloud Storage for Batch Processing.