Confused about VPI driver and EN driver


I have a ConnectX5-EN adapter and use it by VPI driver, but curious about the meaning of EN driver.

What’s the difference between them?

The device info is as follows:

CX515A-CCAT 100GbE

The EN driver file says that :

What’s the meaning? Does it mean that if I install EN driver, I will not be able to run RDMA-based programs?

Very confused about it?

Which driver should I use?