Process substitution

I suppose I should go buy a reference on BASH, but even the basic stuff never fails to amaze me. In doing more research on how to do a remote diff (see my last post), I found that another way to do similar thing using process substitution:

$ diff <(cat FILE1) <(ssh remote-host cat remote-path/FILE1)
$ diff FILE1 <(ssh remote-host cat remote-path/FILE1)