Some concept confused for Azure Service Bus EventHub

Currently, I’m trying to use the Azure Service Bus Event hub and I have some concepts a little bit confused:

1. I have create an event hub (our requirement is send 10Kb data per seconds to the event hub), the hub include 10 partitions, then we receive the data using theEventHubReceiver, when I create the instance for the EventHubReceiver, it need thePartitionId, so I want to know which partitionId is needed?  I guess all the Partitions have the same data which I sended, is it right?
2. Is the PartitionId equals PartitionKey? My understanding is the PartitionId is the indicator for the Partitions in the Event Hub, the PartitionKey is the indicator for the device which send the data, so one Partition can contains many partitonIds,is it right?
3. When we receive data from hub, we need set the Consumer Group, so what is the relationship between EventHub and Consumer group?
4. When we use the EventProcessorHostto receive data, we do not to set the PartitionId, so the data we got is the all PartitionData?
5. When we call the PartitionContext.CheckpointAsync(), the Event hub will do the things to release the Events(delete, clear or sth) by itself, we needn’t do it in our code, is it right?

Is there a diagram to show the relationship for concepts of the EventHub?

Thanks a lot!