What is the difference between Pytorch's DataParallel and DistributedDataParallel?

Question

I am going through this imagenet example.

And, in line 88, the module DistributedDataParallel is used. When I searched for the same in the docs, I haven’t found anything. However, I found the documentation for DataParallel.

So, would like to know what is the difference between the DataParallel and DistributedDataParallel modules.